Salofalk: Uses, Dosage & Side Effects
An aminosalicylate (5-ASA) preparation containing mesalazine, used to treat and maintain remission in mild to moderate ulcerative colitis
Salofalk contains the active substance mesalazine (also known as mesalamine or 5-aminosalicylic acid), which belongs to a group of medicines called aminosalicylates. It is one of the most widely prescribed treatments for ulcerative colitis, a chronic inflammatory bowel disease that affects the lining of the large intestine and rectum. Salofalk is used both to treat acute flares of mild to moderate ulcerative colitis and to maintain remission and prevent relapse. Unlike systemic immunosuppressants, mesalazine works primarily through a local anti-inflammatory effect on the intestinal mucosa, giving it a favourable long-term safety profile. It is included on the WHO Model List of Essential Medicines and is recommended as first-line therapy by all major international gastroenterology guidelines.
Quick Facts: Salofalk
Key Takeaways
- Salofalk contains mesalazine (5-ASA), the first-line treatment for mild to moderate ulcerative colitis; it is recommended by all major international guidelines (ACG, ECCO, BSG, AGA) and is on the WHO Model List of Essential Medicines.
- Mesalazine works locally in the gut lining to reduce inflammation without suppressing the immune system systemically, giving it a much more favourable long-term safety profile than immunosuppressants or biologic agents.
- Kidney function (serum creatinine, eGFR) should be checked before starting Salofalk and monitored regularly during treatment, as rare cases of renal impairment including interstitial nephritis have been reported with mesalazine use.
- Common side effects are generally mild and include headache, nausea, and abdominal discomfort; rare but serious adverse effects include blood dyscrasias, cardiac hypersensitivity (myocarditis/pericarditis), and severe skin reactions.
- Continuous long-term treatment is essential for maintaining remission in ulcerative colitis; stopping mesalazine therapy significantly increases the risk of relapse, and the medication may also have a protective effect against colorectal cancer.
What Is Salofalk and What Is It Used For?
Salofalk is a brand-name medication containing mesalazine, also known internationally as mesalamine or 5-aminosalicylic acid (5-ASA). Mesalazine is the active anti-inflammatory component of sulfasalazine, a drug that has been used in the treatment of ulcerative colitis since the 1940s. When researchers discovered that most of sulfasalazine's therapeutic benefit came from the 5-ASA moiety rather than the sulfonamide carrier, pure mesalazine formulations were developed to deliver the same efficacy with fewer side effects. Salofalk was among the first of these dedicated mesalazine products and remains one of the most widely prescribed globally.
Mesalazine exerts its therapeutic effect primarily through a topical (local) anti-inflammatory action on the colonic and rectal mucosa. Its mechanism of action is multifaceted and involves several pathways. Mesalazine inhibits the enzyme cyclooxygenase (COX) in the intestinal wall, thereby reducing the local production of prostaglandins, which are key mediators of inflammation. It also inhibits the lipoxygenase pathway, decreasing the synthesis of leukotrienes, which are potent pro-inflammatory mediators involved in recruiting white blood cells to the inflamed bowel wall. Additionally, mesalazine acts as a scavenger of reactive oxygen species (free radicals) that cause oxidative damage to the intestinal epithelium, and it may inhibit the activation of nuclear factor kappa-B (NF-kB), a key transcription factor in the inflammatory cascade. Some evidence suggests that mesalazine also modulates the mucosal immune response by reducing the production of pro-inflammatory cytokines such as interleukin-1 (IL-1) and tumour necrosis factor alpha (TNF-alpha).
The critical distinction between mesalazine and systemic immunosuppressive drugs (such as azathioprine, methotrexate, or biologic agents like infliximab and adalimumab) is that mesalazine acts predominantly at the site of disease in the gut wall rather than suppressing the immune system throughout the body. This local mechanism of action is what gives mesalazine its excellent long-term safety profile and makes it suitable as a maintenance therapy that many patients take for years or even decades. Approximately 20–30% of an oral dose of mesalazine is absorbed systemically, with the majority of the drug remaining in the gastrointestinal tract where it exerts its therapeutic effect. The absorbed portion is rapidly acetylated in the intestinal mucosa and liver to the inactive metabolite N-acetyl-5-ASA, which is then excreted renally.
Salofalk is specifically indicated for the following clinical uses:
- Treatment of acute flares of ulcerative colitis: Salofalk is the recommended first-line treatment for inducing remission in patients with mild to moderate ulcerative colitis. Clinical trials have consistently demonstrated that oral mesalazine at doses of 2–4.8 g per day is significantly more effective than placebo for achieving clinical and endoscopic remission in active ulcerative colitis.
- Maintenance of remission in ulcerative colitis: After achieving remission, ongoing mesalazine therapy is the standard approach to prevent relapse. Randomised controlled trials show that mesalazine maintenance therapy reduces the annual relapse rate from approximately 60–70% (with placebo) to 30–40%, and this benefit persists over many years of treatment.
- Chemoprevention of colorectal cancer: Long-standing ulcerative colitis is a significant risk factor for colorectal cancer. Observational studies and meta-analyses suggest that long-term mesalazine use may reduce the risk of colorectal cancer and dysplasia in patients with ulcerative colitis, though this benefit is not yet proven by randomized controlled trials. Several international guidelines acknowledge this potential chemopreventive effect as an additional reason to continue maintenance therapy.
The various Salofalk formulations use specific pharmaceutical technologies to deliver mesalazine to the target site in the gut. Salofalk granules and tablets use a pH-dependent coating (Eudragit L) that remains intact in the acidic environment of the stomach but dissolves when the pH rises to 6 or above, which occurs in the terminal ileum and colon. This ensures that the active drug is released primarily in the large intestine where it is needed. Different mesalazine brands use different release mechanisms: Pentasa uses ethylcellulose microgranules for continuous release throughout the GI tract, while Asacol uses a coating that dissolves at pH 7 or above. The choice of formulation may be influenced by the distribution and extent of disease.
Mesalazine is primarily effective in ulcerative colitis and is considered less effective for Crohn's disease, for which the evidence is weaker and guidelines generally do not recommend it as first-line therapy. If you have been diagnosed with Crohn's disease, your doctor may recommend alternative treatments. The distinction between ulcerative colitis and Crohn's disease is important for selecting the most appropriate therapy.
What Should You Know Before Taking Salofalk?
Contraindications
There are specific situations where Salofalk must not be used. Understanding these absolute contraindications is essential for safe medication use and helps prevent serious adverse reactions.
- Hypersensitivity to mesalazine or salicylates: Do not take Salofalk if you have a known allergy to mesalazine (5-aminosalicylic acid), any other salicylate (such as aspirin or sulfasalazine), or any of the excipients in the product. Allergic reactions can range from mild skin rashes to severe systemic reactions including anaphylaxis.
- Severe hepatic impairment: Salofalk is contraindicated in patients with severe liver disease (hepatic impairment), as the liver is involved in the metabolism of absorbed mesalazine. Patients with significant liver dysfunction may be unable to adequately process the drug, leading to accumulation and increased risk of adverse effects.
- Severe renal impairment: Patients with severe kidney disease (renal impairment) should not use Salofalk. The kidneys excrete the absorbed mesalazine and its metabolites, and impaired renal function increases the risk of further kidney damage. The GFR (glomerular filtration rate) threshold below which mesalazine should be avoided is generally considered to be less than 20 ml/min, though close monitoring is advised even with moderate renal impairment.
Warnings and Precautions
Several important warnings and precautions should be considered before starting and during treatment with Salofalk. Your doctor will weigh the benefits against the risks for your individual situation.
- Pulmonary disease: Patients with pre-existing lung disease, particularly asthma, require careful monitoring during mesalazine therapy. Rare cases of mesalazine-induced pulmonary toxicity have been reported, including eosinophilic pneumonia, allergic alveolitis, and pulmonary fibrosis. Patients should report any new or worsening respiratory symptoms such as cough, shortness of breath, or wheezing to their doctor immediately.
- Sulfasalazine intolerance: Patients who have previously experienced adverse reactions to sulfasalazine should be started on mesalazine with caution and under close medical supervision. While many patients who are intolerant of sulfasalazine (due to its sulfonamide component) can tolerate mesalazine without problems, some patients may also react to the 5-ASA moiety. Treatment should be initiated at a low dose and the patient monitored for several weeks before increasing to the full therapeutic dose.
- Kidney monitoring: Mesalazine can rarely cause renal impairment, including interstitial nephritis, nephrotic syndrome, and renal failure. Renal function (serum creatinine, blood urea nitrogen, and estimated glomerular filtration rate) should be assessed before starting treatment, after 3 months, and then at least annually during long-term therapy. Patients with pre-existing renal impairment should be monitored more frequently. If renal function deteriorates during treatment, mesalazine should be discontinued and the cause investigated.
- Kidney stones: Cases of nephrolithiasis (kidney stones) have been reported with mesalazine use, including stones containing mesalazine as a component. Adequate fluid intake during treatment is recommended to reduce this risk.
- Blood disorders: Mesalazine can rarely cause blood dyscrasias including agranulocytosis, aplastic anaemia, pancytopenia, neutropenia, leukopenia, and thrombocytopenia. A complete blood count should be performed before starting treatment and periodically during therapy. Patients should be advised to seek immediate medical attention if they develop unexplained bruising, bleeding, purpura, sore throat, fever, or malaise during treatment.
- Hepatic function: Elevations in liver transaminases and other markers of liver function have been reported with mesalazine. Liver function tests should be performed before starting treatment and periodically during therapy, particularly in patients with pre-existing liver disease.
Renal function should be checked before starting mesalazine and monitored regularly during treatment (recommended: before treatment, at 3 months, then at least annually). Rare cases of nephrotoxicity, including interstitial nephritis, have been reported. If you notice changes in urine output, swelling, or unexplained fatigue, contact your doctor promptly. Patients with pre-existing kidney disease require more frequent monitoring.
Very rarely, mesalazine can cause severe, life-threatening skin reactions including Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS), Stevens-Johnson Syndrome (SJS), and Toxic Epidermal Necrolysis (TEN). These reactions typically occur within the first weeks of treatment. Seek immediate medical attention if you develop a widespread skin rash with blistering or peeling, fever, swollen lymph nodes, or involvement of mucous membranes (mouth, eyes, genitals). Stop taking the medication immediately and do not restart mesalazine if these reactions are suspected.
Pregnancy and Breastfeeding
Mesalazine is one of the few inflammatory bowel disease treatments that is generally considered to have an acceptable safety profile during pregnancy. Active ulcerative colitis during pregnancy carries significant risks to both the mother and the fetus, including preterm birth, low birth weight, and pregnancy complications. Maintaining disease remission is therefore a priority, and the risks of uncontrolled disease generally outweigh the risks of continuing mesalazine therapy.
Clinical data from large cohort studies and registries have not shown an increased risk of congenital malformations with mesalazine use during pregnancy at standard therapeutic doses. However, very high doses (above 3 g/day) have been associated in some studies with a possible small increase in risk, though this finding is not consistent across all studies. International guidelines, including those from ECCO and the British Society of Gastroenterology, recommend that mesalazine can be continued during pregnancy when clinically indicated, using the lowest effective dose.
Mesalazine and its metabolite N-acetyl-5-ASA pass into breast milk in small amounts. Isolated cases of diarrhea in breastfed infants have been reported. Breastfeeding is generally considered acceptable during mesalazine treatment, but the infant should be monitored for any signs of gastrointestinal disturbance such as diarrhea. If the infant develops diarrhea, the mother should consult her physician. The decision to continue breastfeeding should be made on an individual basis, weighing the benefits of breastfeeding against the small potential risk to the infant.
Driving and Using Machines
Mesalazine has no known or negligible influence on the ability to drive and use machines. Patients can generally continue their normal activities including driving during treatment with Salofalk. However, if you experience dizziness (an uncommon side effect), you should avoid driving or operating machinery until the symptom resolves.
How Does Salofalk Interact with Other Drugs?
While mesalazine has relatively few systemic drug interactions compared to many other medications, there are several important interactions that prescribers and patients should be aware of. The limited systemic absorption of mesalazine (approximately 20–30% of an oral dose) means that interactions are less common than with drugs that are fully absorbed, but they can still be clinically significant.
Major Interactions
The following interactions are considered clinically significant and may require dose adjustment, additional monitoring, or avoidance of the combination.
| Interacting Drug | Effect | Clinical Significance |
|---|---|---|
| Azathioprine / 6-Mercaptopurine / Thioguanine | Mesalazine inhibits the enzyme thiopurine methyltransferase (TPMT), which metabolises thiopurine drugs. This can increase levels of active thiopurine metabolites (6-thioguanine nucleotides), leading to enhanced myelosuppression (bone marrow suppression). | High. This combination is common in clinical practice (step-up therapy in IBD). Complete blood counts should be monitored more frequently. The dose of azathioprine or 6-mercaptopurine may need to be reduced. Symptoms of myelosuppression include unexplained infections, bruising, or fatigue. |
| Warfarin | Mesalazine may reduce the anticoagulant effect of warfarin through an unclear mechanism, possibly by competing for protein binding or affecting vitamin K metabolism in the gut. | Moderate. INR should be monitored more closely when mesalazine is started, stopped, or the dose is changed in patients taking warfarin. Dose adjustment of warfarin may be necessary. |
Minor Interactions
The following interactions are of lower clinical significance but should still be considered, particularly in patients with additional risk factors.
| Interacting Drug | Effect | Clinical Significance |
|---|---|---|
| Lactulose and other stool pH-lowering agents | Lactulose lowers stool pH through bacterial fermentation to lactic acid. Since some mesalazine formulations (including Salofalk) rely on pH-dependent coating that dissolves at pH 6 or above, a significantly lowered colonic pH may theoretically impair drug release. | Low. The clinical relevance is uncertain. If poor response to mesalazine is observed in a patient taking lactulose, consideration should be given to this interaction. The effect is unlikely to be significant in most patients. |
| NSAIDs (e.g., ibuprofen, naproxen, diclofenac) | Both mesalazine and NSAIDs can cause renal side effects. Concurrent use may increase the risk of nephrotoxicity, particularly interstitial nephritis and impaired renal function. | Low to moderate. NSAIDs should be used with caution in patients taking mesalazine, particularly those with pre-existing renal impairment. NSAIDs may also exacerbate ulcerative colitis symptoms. Regular renal function monitoring is advisable. |
Mesalazine may also interact with certain laboratory tests. It can interfere with the measurement of urinary normetanephrine (a metabolite of noradrenaline) by HPLC methods, potentially producing false-positive results. If you are undergoing any laboratory testing, inform the laboratory that you are taking mesalazine.
There is no clinically significant interaction between mesalazine and proton pump inhibitors (PPIs), which are commonly co-prescribed in gastroenterology patients. Mesalazine does not interact with hormonal contraceptives and does not reduce their effectiveness. Alcohol consumption does not affect the pharmacokinetics or efficacy of mesalazine, though patients with active ulcerative colitis are generally advised to avoid alcohol as it may worsen gut inflammation.
Always inform your doctor and pharmacist about all medications you are taking, including over-the-counter drugs, herbal remedies, and dietary supplements. This is particularly important if you are taking immunosuppressive drugs (azathioprine, 6-mercaptopurine), anticoagulants (warfarin), or regular NSAIDs, as dose adjustments or additional monitoring may be required.
What Is the Correct Dosage of Salofalk?
The dosage of Salofalk depends on whether the medication is being used to treat an acute flare of ulcerative colitis or to maintain remission, as well as on the specific formulation being used. The following dosage information reflects standard prescribing recommendations based on international guidelines and product labelling. Always follow the dosage instructions given by your prescribing physician, as individual doses may vary based on disease severity, extent, and response to treatment.
Adults – Acute Treatment
Acute Flare (Induction of Remission)
The standard dose for treating an active flare of mild to moderate ulcerative colitis is 1.5 g to 3 g of mesalazine per day, taken in divided doses (typically three times daily) or as a single daily dose depending on the formulation. Some guidelines and formulations allow doses up to 4 g per day or even 4.8 g per day for moderate disease. Higher doses within this range are generally more effective for inducing remission. The usual duration of acute treatment is 8 weeks, though your doctor may adjust this based on your response.
Maintenance of Remission
After achieving remission, the recommended maintenance dose is 1.5 g per day. However, for patients who have frequent relapses or more extensive disease, doses of up to 3 g per day may be used for maintenance. International guidelines emphasize that maintenance therapy should be continued indefinitely, as stopping treatment significantly increases the risk of relapse. Once-daily dosing has been shown to be at least as effective as divided doses for maintenance, and may improve adherence.
Children (6 Years and Older)
Mesalazine is used in paediatric patients with ulcerative colitis, typically from 6 years of age. Dosing in children is weight-based. The recommended dose for active disease is approximately 30–50 mg per kilogram of body weight per day, divided into multiple doses, up to a maximum of the standard adult dose. For maintenance of remission, the dose is approximately 15–30 mg/kg/day. Paediatric dosing should always be determined by a specialist with experience in treating paediatric inflammatory bowel disease.
Elderly Patients
No specific dose adjustment is generally required for elderly patients. However, as renal function naturally declines with age, elderly patients should have their kidney function assessed before starting treatment and monitored more frequently during therapy. Caution is advised in elderly patients with any degree of renal impairment, and the lowest effective dose should be used.
| Indication | Population | Dose | Duration |
|---|---|---|---|
| Acute flare (mild) | Adults | 1.5–3 g/day | 6–8 weeks |
| Acute flare (moderate) | Adults | 3–4.8 g/day | 8 weeks |
| Maintenance of remission | Adults | 1.5–3 g/day | Long-term / indefinite |
| Active disease | Children (6+ years) | 30–50 mg/kg/day (max adult dose) | 6–8 weeks |
| Maintenance | Children (6+ years) | 15–30 mg/kg/day | Long-term |
Missed Dose
If you miss a dose of Salofalk, take it as soon as you remember unless it is almost time for your next scheduled dose. In that case, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you frequently forget to take your medication, speak to your doctor about whether a once-daily dosing regimen might be more suitable, as once-daily dosing has been shown to be at least as effective as divided doses for maintenance therapy and can significantly improve adherence.
Overdose
Experience with mesalazine overdose is limited. Because mesalazine is a salicylate, large overdoses could theoretically produce symptoms similar to salicylate toxicity, including nausea, vomiting, abdominal pain, diarrhoea, tinnitus (ringing in the ears), and in severe cases metabolic acidosis and renal impairment. However, since mesalazine is much less potently absorbed than aspirin, the risk of severe systemic toxicity is lower. In the event of a suspected overdose, seek immediate medical attention. Treatment is supportive and symptomatic, with particular attention to fluid balance and renal function.
Non-adherence to mesalazine maintenance therapy is the single most important modifiable risk factor for relapse in ulcerative colitis. Studies show that patients who take less than 80% of their prescribed doses have a significantly higher risk of relapse. If you find it difficult to take your medication as prescribed, discuss this with your doctor, as simpler dosing regimens (such as once-daily dosing) may improve adherence without reducing efficacy.
What Are the Side Effects of Salofalk?
Like all medicines, Salofalk can cause side effects, although not everybody gets them. Most side effects with mesalazine are mild to moderate and often resolve with continued treatment or dose adjustment. Mesalazine has been used extensively for over 30 years, and its overall safety profile is well established through clinical trials and post-marketing surveillance. The following side effects are classified according to their frequency of occurrence based on data from clinical trials and post-marketing reports.
Common
- Headache
- Skin rash (including urticaria/hives)
- Itching (pruritus)
Uncommon
- Abdominal pain and cramps
- Diarrhoea
- Nausea
- Vomiting
- Flatulence (excess gas)
- Acute pancreatitis (inflammation of the pancreas)
- Elevated liver enzymes (transaminases) and bilirubin
- Dizziness
Rare
- Photosensitivity (increased sensitivity to sunlight)
- Joint pain (arthralgia)
- Muscle pain (myalgia)
- Fatigue and malaise
- Cholestatic hepatitis and jaundice
Very Rare
- Peripheral neuropathy (numbness, tingling in hands or feet)
- Pulmonary infiltrates and allergic lung reactions (eosinophilic pneumonia, allergic alveolitis)
- Hair loss (alopecia)
- Reduced sperm count and motility (oligospermia) – reversible on stopping the drug
- Kidney damage (interstitial nephritis, nephrotic syndrome, renal failure)
- Kidney stones (nephrolithiasis)
- Changes in blood cell counts (leukopenia, thrombocytopenia, eosinophilia)
Seek urgent medical attention if you experience any of the following rare but serious reactions during treatment with Salofalk:
- Blood disorders: Agranulocytosis (severe decrease in white blood cells), aplastic anaemia (bone marrow failure), or pancytopenia. Symptoms include unexplained fever, sore throat, infections, unusual bruising or bleeding, and severe fatigue.
- Cardiac hypersensitivity: Myocarditis (inflammation of the heart muscle) or pericarditis (inflammation of the sac around the heart). Symptoms include chest pain, shortness of breath, rapid heartbeat, and fever. These typically occur within the first few weeks of treatment.
- Severe skin reactions: Stevens-Johnson Syndrome (SJS), Toxic Epidermal Necrolysis (TEN), or Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS). Symptoms include widespread rash with blistering, peeling skin, fever, and involvement of the mouth, eyes, or genitals.
- Acute pancreatitis: Severe, persistent upper abdominal pain that may radiate to the back, often accompanied by nausea and vomiting.
It is important to distinguish between side effects of mesalazine and symptoms of a flare of ulcerative colitis itself, as both can cause diarrhoea, abdominal pain, and rectal bleeding. If your symptoms worsen after starting or increasing the dose of mesalazine, your doctor may need to determine whether this represents a worsening of the underlying disease or a rare hypersensitivity reaction to the medication. In very rare cases, mesalazine can paradoxically worsen colitis symptoms through a hypersensitivity mechanism, and if this is suspected, the medication should be discontinued.
The effect of mesalazine on male fertility deserves special mention. Oligospermia (reduced sperm count) and reduced sperm motility have been reported with mesalazine, although this effect appears to be less common and less severe than the well-documented effect of sulfasalazine on male fertility. The effect is believed to be reversible upon discontinuation of the drug. Men who are experiencing difficulty conceiving should discuss this with their doctor, who may recommend a semen analysis.
Long-term safety data from observational studies and clinical practice over more than three decades confirm that mesalazine is one of the safest long-term medications available for chronic inflammatory bowel disease. The overall incidence of serious adverse effects requiring treatment discontinuation is estimated at approximately 2–5% in clinical trials. Most patients tolerate mesalazine well over many years of continuous use.
How Should You Store Salofalk?
Salofalk should be stored at room temperature, generally below 25°C (77°F), unless the specific product labelling states otherwise. The granules and tablets should be kept in their original packaging to protect the pH-sensitive coating from moisture, which could affect the drug release mechanism. Do not store in the bathroom or other humid environments, and do not expose to direct sunlight or excessive heat.
Keep this medicine out of the sight and reach of children. Children are particularly susceptible to accidental ingestion of medications, and Salofalk granules may look attractive to young children. Store the medication in a secure location that is not accessible to children.
Always check the expiry date on the packaging before taking the medication. Do not use Salofalk after the expiry date which is stated on the carton and sachet or blister pack. The expiry date refers to the last day of that month. Expired medications may have reduced potency and the integrity of the pH-dependent coating may be compromised, affecting drug release and efficacy.
Do not dispose of unused or expired medications via household waste or wastewater. This protects the environment and prevents accidental exposure to others. Return any unused medication to your pharmacist for proper disposal according to local regulations.
What Does Salofalk Contain?
The composition of Salofalk varies slightly depending on the specific formulation (granules, tablets), but all products contain mesalazine as the active substance. The following information describes the composition of the most commonly prescribed formulation.
Active Substance
Each sachet of Salofalk 500 mg prolonged-release granules contains 500 mg mesalazine (also known as 5-aminosalicylic acid or 5-ASA). Each sachet of Salofalk 1000 mg (1 g) prolonged-release granules contains 1000 mg mesalazine. Mesalazine is a white to slightly pinkish or greyish-white powder with anti-inflammatory properties specific to the gastrointestinal mucosa.
Excipients (Inactive Ingredients)
The excipients in Salofalk prolonged-release granules serve specific pharmaceutical purposes, including controlling the site and rate of drug release, improving palatability, and ensuring stability. Common excipients include:
- Aspartame (E 951): An artificial sweetener used to improve the taste of the granules. Each 500 mg sachet contains approximately 1.5 mg aspartame. Aspartame is a source of phenylalanine.
- Carmellose sodium: A cellulose derivative used as a disintegrant and binder.
- Microcrystalline cellulose: Used as a filler and binder to form the granule structure.
- Citric acid anhydrous: Used to adjust the internal pH of the granule formulation.
- Hypromellose: A cellulose derivative used in the coating system.
- Methacrylic acid copolymer (Eudragit L): The pH-dependent coating that prevents drug release in the stomach and ensures mesalazine is released in the terminal ileum and colon (at pH 6 and above).
- Simeticone: An antifoaming agent used in the manufacturing process.
- Sorbic acid: A preservative.
- Talc: Used in the coating system as a glidant.
- Titanium dioxide: Used as a white colourant in the coating.
Salofalk prolonged-release granules contain aspartame (E 951), which is a source of phenylalanine. Patients with phenylketonuria (PKU) should be aware of this and discuss it with their doctor. The amount of phenylalanine per sachet is small (approximately 0.84 mg per 500 mg sachet), but should be considered when calculating the total daily phenylalanine intake for patients on a phenylalanine-restricted diet.
Frequently Asked Questions
Salofalk, Pentasa, Asacol, and Mezavant all contain the same active ingredient, mesalazine (5-ASA), but they differ in their pharmaceutical release mechanisms. Salofalk uses a pH-dependent coating (Eudragit L) that dissolves at pH 6 or above, releasing the drug primarily in the terminal ileum and colon. Pentasa uses ethylcellulose microgranules for time-dependent release throughout the entire gastrointestinal tract. Asacol uses a different pH-dependent coating that dissolves at pH 7 or above, targeting the colon more specifically. Mezavant uses a multi-matrix (MMX) system for once-daily dosing with colonic release. The choice of product may depend on the location and extent of disease, patient preference, and prescriber experience. All are considered therapeutically equivalent for most patients with ulcerative colitis.
Rarely, mesalazine can cause renal impairment including interstitial nephritis (inflammation of the kidney tissue) and nephrotic syndrome. These are idiosyncratic reactions, meaning they are unpredictable and not directly related to the dose. The risk is very low (estimated at less than 1 in 500 patients) but kidney function should be checked before starting treatment and monitored periodically during therapy, particularly in the first year. Most cases occur within the first 12 months. If kidney function deteriorates, mesalazine should be discontinued promptly. In many cases, renal function improves after the drug is stopped, though some patients may sustain permanent kidney damage if the problem is not detected early. This is why regular monitoring with blood tests (serum creatinine, eGFR) is recommended.
Some patients may notice improvement in their symptoms within the first 1 to 2 weeks of starting Salofalk, but the full therapeutic effect for an acute flare typically requires 4 to 8 weeks of continuous treatment. Clinical trials assessing the efficacy of mesalazine for induction of remission use 6 to 8 week endpoints. If there is no improvement after 8 weeks of treatment at an adequate dose, your doctor may consider increasing the dose, adding topical (rectal) mesalazine, or stepping up to a different class of medication. For maintenance therapy, the goal is prevention of relapse, and the benefit is measured over months and years of treatment rather than days.
Yes, mesalazine is generally considered one of the safer medications for inflammatory bowel disease during pregnancy and is widely used in pregnant women with ulcerative colitis. International guidelines (ECCO, BSG, ACG) recommend that mesalazine can be continued during pregnancy when clinically indicated. Active disease during pregnancy poses greater risks to both the mother and baby (including preterm birth, low birth weight, and pregnancy complications) than the medication itself. Large registry studies have not shown an increased risk of major birth defects with standard doses. Very high doses (above 3 g/day) may warrant additional caution. The decision should always be made in consultation with your gastroenterologist and obstetrician.
No, mesalazine is not an immunosuppressant and does not suppress the immune system in the way that drugs like azathioprine, methotrexate, or biologic agents (infliximab, adalimumab) do. Mesalazine works primarily through local anti-inflammatory effects in the gut wall, reducing prostaglandin and leukotriene production and scavenging reactive oxygen species. This means it does not increase your overall risk of infections, does not require vaccination precautions, and does not carry the same risks associated with systemic immunosuppression. This favourable safety profile is one of the key reasons why mesalazine is recommended as the preferred first-line treatment for mild to moderate ulcerative colitis. Patients on mesalazine alone can receive all standard vaccines, including live vaccines.
If your ulcerative colitis symptoms worsen or do not improve despite taking Salofalk as prescribed, contact your doctor promptly rather than adjusting the dose yourself. There are several possible explanations: the current dose may be insufficient and need increasing; you may need additional rectal (topical) mesalazine therapy; the disease may have progressed to a severity that requires escalation to immunosuppressive or biologic treatments; or, rarely, you may be experiencing a hypersensitivity reaction to mesalazine itself, which can paradoxically mimic a flare of colitis. Your doctor can distinguish between these possibilities through clinical assessment, laboratory tests, and if necessary, endoscopy. Never stop Salofalk abruptly without medical advice, as sudden discontinuation can trigger a disease flare.
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Editorial Team
This article has been written and reviewed by the iMedic medical editorial team according to our strict editorial standards. Our team consists of licensed physicians, pharmacists, and medical researchers with expertise in clinical pharmacology and gastroenterology.
Content developed by iMedic's medical writing team based on current international guidelines (WHO, EMA, FDA, BNF, ACG, ECCO) and peer-reviewed pharmacological and gastroenterological research.
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