Tetralysal (Lymecycline)
Tetracycline antibiotic for acne and bacterial infections
Tetralysal is a prescription tetracycline antibiotic containing the active substance lymecycline. It is primarily used to treat moderate to severe acne vulgaris, acute exacerbations of chronic bronchitis, certain types of pneumonia, and chlamydia infections. Lymecycline works by inhibiting bacterial protein synthesis, thereby preventing bacterial growth. This comprehensive guide covers uses, dosage, side effects, drug interactions, and important safety information based on international clinical guidelines.
Quick Facts
Key Takeaways
- Tetralysal (lymecycline) is a tetracycline antibiotic effective against acne-causing bacteria and has anti-inflammatory properties that help reduce acne lesions.
- The standard adult dose for acne is 300 mg once daily, typically prescribed for 8 to 12 weeks; for other infections, the dose is usually 300 mg twice daily.
- Avoid sun exposure and tanning beds during treatment due to increased photosensitivity; always use sunscreen when outdoors.
- Do not take Tetralysal with oral retinoids (such as isotretinoin) due to the serious risk of increased intracranial pressure (pseudotumor cerebri).
- Not recommended for children under 8 years, pregnant women, or breastfeeding mothers due to risks of tooth discoloration and skeletal damage in developing children.
What Is Tetralysal and What Is It Used For?
Tetralysal contains the active substance lymecycline, a semi-synthetic tetracycline antibiotic. Lymecycline is a prodrug formed by combining the amino acid lysine with tetracycline through a formaldehyde bridge. Once ingested, it is rapidly converted to tetracycline in the body, where it exerts its bacteriostatic effect by binding to the 30S subunit of bacterial ribosomes. This prevents the attachment of aminoacyl-tRNA to the mRNA-ribosome complex, effectively stopping bacterial protein synthesis and halting bacterial growth and reproduction.
The most common use of Tetralysal worldwide is in the treatment of acne vulgaris, particularly moderate to severe inflammatory acne affecting the face. Tetracyclines have been a cornerstone of systemic acne therapy for decades, and lymecycline is preferred by many dermatologists due to its favorable absorption profile and tolerability. In acne, lymecycline targets Cutibacterium acnes (formerly known as Propionibacterium acnes), the bacterium primarily responsible for the inflammatory component of acne. Beyond its antibacterial effect, lymecycline also possesses significant anti-inflammatory properties: it inhibits the production of pro-inflammatory cytokines including interleukin-1 (IL-1), tumor necrosis factor alpha (TNF-alpha), and matrix metalloproteinases (MMPs), all of which contribute to the redness, swelling, and tissue damage seen in inflammatory acne.
Beyond acne, Tetralysal is prescribed for several other bacterial infections. It is used in the treatment of acute exacerbations of chronic bronchitis, where bacterial superinfection (often by organisms such as Haemophilus influenzae or Moraxella catarrhalis) complicates underlying chronic obstructive pulmonary disease. Tetralysal is also effective against atypical pneumonia caused by organisms such as Mycoplasma pneumoniae, Chlamydophila pneumoniae, and Legionella pneumophila — pathogens that are intrinsically resistant to beta-lactam antibiotics but susceptible to tetracyclines.
Another important indication is chlamydia infections, particularly uncomplicated urogenital infections caused by Chlamydia trachomatis. In regions where doxycycline is not available or not tolerated, lymecycline represents an effective alternative for chlamydia treatment. The World Health Organization (WHO) recognizes tetracyclines as a key antibiotic class for the management of sexually transmitted infections.
It is important to note that Tetralysal, like all antibiotics, is only effective against bacterial infections. It does not work against viral infections such as the common cold or influenza. Inappropriate use of antibiotics contributes to the global problem of antimicrobial resistance, and Tetralysal should only be used when prescribed by a healthcare professional who has determined that antibiotic treatment is necessary.
What Should You Know Before Taking Tetralysal?
Contraindications
There are certain situations where Tetralysal must not be used. Understanding these contraindications is essential for safe prescribing and patient safety. The following are absolute contraindications to Tetralysal use:
- You are allergic to lymecycline, tetracycline, or any other tetracycline antibiotic, or to any of the other ingredients in the capsule (including gelatin, lactose, or colorants such as erythrosine E127 or quinoline yellow E104).
- You are currently taking oral retinoids such as isotretinoin (Accutane/Roaccutane), etretinate, or acitretin, which are used to treat severe acne and psoriasis. The combination greatly increases the risk of raised intracranial pressure.
Cross-sensitivity can occur between different tetracycline antibiotics. If you have previously experienced an allergic reaction to doxycycline, minocycline, or any other tetracycline, inform your doctor before taking Tetralysal, as you may be at increased risk of a similar reaction to lymecycline.
Warnings and Precautions
Before starting Tetralysal, speak with your doctor or pharmacist if any of the following conditions apply to you, as they may require closer monitoring or dose adjustment:
- Kidney disease or impairment: Tetracyclines are partly excreted by the kidneys, and impaired renal function can lead to accumulation and increased risk of side effects. Your doctor may need to reduce the dose or choose an alternative antibiotic.
- Myasthenia gravis: Tetracyclines may worsen muscle weakness in patients with this neuromuscular condition. Tetralysal should be used with great caution, and patients should be monitored for any deterioration in muscle function.
- Systemic lupus erythematosus (SLE): There have been reports of tetracycline antibiotics exacerbating or triggering lupus flares. Patients with SLE should discuss the risks and benefits with their doctor before starting treatment.
Tetralysal can cause increased sensitivity to sunlight (photosensitivity). During treatment, you should avoid direct sunlight, sunbathing, and UV radiation (including tanning beds/solariums). If sun exposure is unavoidable, use a broad-spectrum sunscreen with SPF 30 or higher and wear protective clothing. If you develop an exaggerated sunburn or unusual skin reaction, stop taking Tetralysal and contact your doctor immediately.
- Angioedema: Swelling of the face, tongue, or throat, difficulty swallowing, hives, or breathing difficulties.
- Signs of raised intracranial pressure: Severe headache with visual disturbances (blurred vision, double vision, dark spots in your field of vision) and nausea or vomiting. This may indicate a condition known as pseudotumor cerebri (benign intracranial hypertension).
Use in Children
Children under 8 years of age should only be treated with Tetralysal in exceptional circumstances. Tetracycline antibiotics accumulate in developing teeth and bones, which can cause permanent tooth discoloration (typically yellow-gray-brown staining) and enamel hypoplasia (defective tooth enamel formation). These effects occur because tetracyclines form irreversible complexes with calcium in teeth and bone during development. Additionally, there is a risk of impaired skeletal development, including decreased bone growth in children. The risk is highest in children under 8 and during the second and third trimesters of pregnancy. For children aged 8 to 12, the decision to prescribe should be made on a case-by-case basis by the treating physician, weighing the severity of the infection against the risks.
Pregnancy and Breastfeeding
Pregnancy: Tetralysal should not be used during pregnancy due to the risk of harm to the developing fetus. Tetracyclines cross the placenta and can accumulate in fetal bones and teeth, potentially causing permanent tooth discoloration and enamel defects in the child. Animal studies have also shown potential effects on skeletal development. If you discover that you are pregnant while taking Tetralysal, stop the medication and contact your doctor immediately.
Breastfeeding: Lymecycline passes into breast milk. Because of the risk of tooth discoloration and skeletal effects on the nursing infant, breastfeeding should be discontinued during treatment with Tetralysal. If antibiotic treatment is necessary during breastfeeding, your doctor can recommend an alternative antibiotic that is considered safe for use while breastfeeding.
Driving and Using Machines
No effects on the ability to drive or operate machinery have been observed with Tetralysal. The medication is not known to cause drowsiness, dizziness, or impaired concentration at standard therapeutic doses. However, if you experience any side effects that could affect your alertness (such as dizziness or visual disturbances), refrain from driving or operating heavy machinery until these effects have resolved.
Lactose Content
Tetralysal 150 mg capsules contain lactose as an excipient. If you have a known intolerance to lactose or other sugars, or if you have been diagnosed with a rare hereditary condition such as galactose intolerance, Lapp lactase deficiency, or glucose-galactose malabsorption, consult your doctor before taking this medicine.
How Does Tetralysal Interact with Other Drugs?
Drug interactions can reduce the effectiveness of Tetralysal or increase the risk of adverse effects. It is essential to inform your doctor or pharmacist about all medications, supplements, and herbal products you are currently taking, have recently taken, or plan to take. Below is a comprehensive overview of known interactions grouped by clinical significance.
Major Interactions (Avoid Combination)
| Drug / Class | Effect of Interaction | Clinical Action |
|---|---|---|
| Oral retinoids (isotretinoin, acitretin, etretinate) | Both drugs can independently raise intracranial pressure; combination significantly increases risk of pseudotumor cerebri | Absolutely contraindicated. Do not use together. |
| High-dose Vitamin A supplements | Similar mechanism to retinoids; risk of raised intracranial pressure | Avoid concurrent use with high-dose Vitamin A preparations. |
Moderate Interactions (Use with Caution)
| Drug / Class | Effect of Interaction | Clinical Action |
|---|---|---|
| Warfarin and other coumarin anticoagulants | Tetracyclines may enhance the anticoagulant effect of coumarins, increasing bleeding risk | Monitor INR closely; dose adjustment of anticoagulant may be required. |
| Lithium | Tetracyclines can increase serum lithium levels, potentially leading to lithium toxicity | Monitor lithium levels during concurrent use; adjust lithium dose as needed. |
| Didanosine (ddI) | The buffered formulation of didanosine contains antacids that reduce tetracycline absorption | Separate administration by at least 2-3 hours. |
| Quinapril | Quinapril tablets contain magnesium carbonate, which can chelate tetracyclines and reduce absorption | Separate doses by at least 2-3 hours. |
Absorption Interactions (Timing Required)
Several substances reduce the absorption of Tetralysal by binding to it in the gastrointestinal tract through a process called chelation. Divalent and trivalent metal cations (calcium, iron, magnesium, zinc, aluminum) form insoluble complexes with tetracyclines, dramatically reducing the amount of drug absorbed into the bloodstream. The following products should be taken at least 3 hours apart from Tetralysal:
- Iron supplements — commonly prescribed for anemia
- Calcium supplements — including calcium carbonate and calcium citrate
- Zinc supplements — often taken for immune support or skin health
- Sucralfate — used for stomach and duodenal ulcers; contains aluminum
- Antacids — products containing aluminum hydroxide, magnesium hydroxide, or calcium carbonate (e.g., Maalox, Gaviscon, Rennie)
Tetralysal can be taken with food to reduce gastrointestinal side effects. However, the effectiveness may be somewhat reduced when taken alongside calcium-rich foods such as milk, yogurt, cheese, or other dairy products. Allow at least 3 hours between taking Tetralysal and consuming dairy products to ensure optimal absorption. Water is the best beverage to take with the capsule.
What Is the Correct Dosage of Tetralysal?
Always use Tetralysal exactly as your doctor has prescribed. Your doctor will determine the appropriate dose based on your specific condition, its severity, and your individual medical profile. Do not change the dose or stop taking the medication without consulting your doctor, even if you start to feel better.
Adults
| Indication | Dosage | Duration | Notes |
|---|---|---|---|
| Bacterial infections (bronchitis, pneumonia, chlamydia) | 300 mg twice daily (morning and evening) | As prescribed (usually 7-14 days) | Complete the full course even if symptoms improve |
| Acne vulgaris | 300 mg once daily | 8-12 weeks typically | Often used alongside topical treatments (benzoyl peroxide, retinoids) |
| Acne (alternative regimen) | 150 mg twice daily | 8-12 weeks | Equivalent total daily dose of 300 mg tetracycline equivalent |
Children and Adolescents
Tetralysal is not recommended for children under 8 years of age due to the risk of permanent tooth discoloration and impaired skeletal development. In adolescents aged 12 and above, the same adult dosing regimen is generally applied for the treatment of acne, which is the most common indication in this age group. For children aged 8 to 12, treatment should only be considered in exceptional circumstances and the dose should be individually determined by the prescribing physician based on body weight and clinical necessity.
Elderly Patients
No specific dose adjustment is generally required in elderly patients with normal kidney function. However, older adults are more likely to have reduced renal function, which may necessitate dose reduction or extended dosing intervals. Your doctor will assess kidney function through blood tests before prescribing Tetralysal and may monitor it during treatment. Elderly patients should also be particularly vigilant about photosensitivity and adequate hydration during treatment.
How to Take Tetralysal
- Carefully tear open the aluminum strip packaging and remove the capsule.
- Swallow the capsule whole — do not open, crush, or chew it.
- Take with at least half a glass of water (approximately 120 ml).
- Take in an upright position (sitting or standing) — do not lie down for at least 30 minutes after taking the capsule to prevent irritation of the esophagus.
- Can be taken with food to reduce stomach upset, but avoid dairy products within 3 hours.
Missed Dose
If you forget to take a dose of Tetralysal, take it as soon as you remember, unless it is nearly 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 forgotten dose. Maintaining consistent dosing is important for achieving optimal antibiotic levels in your blood throughout the treatment course. If you frequently forget doses, consider setting a daily alarm or using a pill organizer to help you remember.
Overdose
If you have taken more Tetralysal than prescribed, or if a child has accidentally swallowed the medication, contact your doctor, hospital emergency department, or poison control center immediately for a risk assessment and advice. Symptoms of tetracycline overdose may include severe nausea, vomiting, and diarrhea. There is no specific antidote for lymecycline overdose, and treatment is supportive, focusing on managing symptoms and maintaining hydration.
What Are the Side Effects of Tetralysal?
Like all medicines, Tetralysal can cause side effects, although not everybody experiences them. Most side effects are mild and temporary, and many resolve as your body adjusts to the medication. Gastrointestinal side effects are the most commonly reported and can often be minimized by taking the capsules with food.
The side effects are listed below according to their frequency of occurrence. Understanding the frequency categories can help you assess the relative risk and know when to contact your doctor:
Common Side Effects
- Nausea
- Abdominal pain (stomach ache)
- Diarrhea
- Headache
Reported (Frequency Not Known)
- Blood disorders (changes in blood cell counts)
- Visual disturbances (may indicate raised intracranial pressure)
- Inflammation of the tongue (glossitis)
- Inflammation of the bowel (enterocolitis)
- Vomiting
- Upper abdominal pain (epigastric pain)
- Fever
- Jaundice (yellowing of the skin and eyes)
- Hepatitis (inflammation of the liver)
- Liver function abnormalities
- Allergic reactions with fever, rash, swelling, and sometimes low blood pressure
- Angioedema (swelling of face, lips, tongue, or throat with potential breathing difficulty)
- Skin rash, itching, or hives (urticaria)
- Dizziness
- Raised intracranial pressure (pseudotumor cerebri)
- Photosensitivity reactions (skin reactions caused by increased sensitivity to light)
- Severe skin and mucosal reactions (including Stevens-Johnson syndrome in rare cases)
- Depression
- Nightmares
Side Effects Associated with the Tetracycline Class
The following side effects have been reported with tetracycline antibiotics as a class and may potentially occur with Tetralysal:
- Tooth discoloration and enamel hypoplasia: Particularly in children under 8 years of age. The discoloration is typically yellow-gray-brown and is permanent. This is why tetracyclines are contraindicated in young children and during pregnancy.
- Kidney effects: Renal impairment may be exacerbated, particularly when diuretics are used concurrently with tetracyclines. Patients with pre-existing kidney disease require careful monitoring.
- Benign intracranial hypertension (pseudotumor cerebri): Characterized by headache, nausea, vomiting, and visual disturbances including blurred vision, scotomas (dark spots or flickering light in the visual field), diplopia (double vision), and in severe cases, permanent vision loss. If you experience any of these symptoms, stop taking the medication immediately and seek urgent medical attention.
- Systemic lupus erythematosus: Exacerbation or new onset of autoimmune lupus has been associated with tetracycline use.
- Pancreatitis: Inflammation of the pancreas has been reported in association with tetracycline therapy.
- Esophageal irritation and ulceration: This is why it is important to take the capsules with plenty of water in an upright position and not lie down immediately afterward.
Contact your doctor if any side effect becomes severe or bothersome, or if you notice any side effects not listed here. Seek emergency medical attention immediately if you experience signs of a severe allergic reaction (difficulty breathing, swelling of the face or throat), severe headache with visual disturbances, or severe skin reactions with blistering.
How Should You Store Tetralysal?
Proper storage of medication is essential to maintain its effectiveness and safety. Lymecycline, like other tetracyclines, can degrade over time, and expired tetracyclines can potentially form toxic degradation products. Follow these storage guidelines carefully:
- Keep this medicine out of the sight and reach of children at all times.
- Store at room temperature (below 25°C / 77°F) unless otherwise stated on the packaging.
- Keep the capsules in their original aluminum strip packaging until ready to take, to protect them from moisture and light.
- Do not use Tetralysal after the expiry date printed on the carton (after “EXP”). The expiry date refers to the last day of that month.
- Do not flush unused medicines down the toilet or throw them in household waste. Return unused or expired medicines to your pharmacy, where they will be disposed of safely in a way that protects the environment.
Using tetracycline antibiotics past their expiry date is particularly inadvisable compared to some other medication classes. Degraded tetracyclines have historically been associated with a reversible form of kidney damage known as Fanconi syndrome, though modern manufacturing processes have largely eliminated the specific degradation product (anhydro-4-epitetracycline) responsible. Nevertheless, always check the expiry date before taking any dose and discard any expired medication promptly.
What Does Tetralysal Contain?
150 mg Capsules
Active substance: Lymecycline equivalent to 150 mg of tetracycline per capsule.
Other ingredients: Gelatin, magnesium stearate, levulose (fructose), cornstarch (maize starch), lactose, titanium dioxide (E171), erythrosine (E127), quinoline yellow (E104).
300 mg Capsules
Active substance: Lymecycline equivalent to 300 mg of tetracycline per capsule.
Other ingredients: Gelatin, magnesium stearate, levulose (fructose), titanium dioxide (E171), erythrosine (E127), quinoline yellow (E104), indigo carmine (E132).
Packaging
Tetralysal is available in aluminum strip packaging containing 20 or 100 capsules per pack. Not all pack sizes may be marketed in all countries. The capsules are individually sealed in strips to protect them from moisture and light degradation.
Marketing Authorization Holder: Galderma Nordic AB (manufactured by Inpac AB, Lund, and Laboratoires Galderma / Laboratoires Sophartex, France).
Frequently Asked Questions About Tetralysal
Tetralysal (lymecycline) is a tetracycline antibiotic primarily used to treat moderate to severe acne vulgaris (facial acne). It is also prescribed for acute exacerbations of chronic bronchitis, certain types of pneumonia (including atypical pneumonia caused by Mycoplasma and Chlamydophila), and chlamydia infections. For acne, it works both by reducing acne-causing bacteria and by its anti-inflammatory properties.
Tetralysal typically takes 6 to 8 weeks to show significant improvement in acne symptoms. Some patients may notice initial improvement within 2 to 4 weeks, but the full therapeutic effect usually requires at least 8 to 12 weeks of continuous treatment. A standard course for acne is usually 8 to 12 weeks, and it is important not to stop the medication early even if results seem slow initially.
While Tetralysal can be taken with food, its effectiveness may be reduced when taken with calcium-rich products such as milk, yogurt, or cheese. Calcium binds to tetracyclines in the gut and reduces absorption. It is recommended to allow at least 3 hours between taking Tetralysal and consuming dairy products, and to avoid taking it with iron, zinc, or calcium supplements.
Tetralysal can cause photosensitivity, meaning your skin may become more sensitive to sunlight and UV radiation. You should avoid excessive sun exposure, sunbathing, and tanning beds during treatment. Use a broad-spectrum sunscreen with SPF 30 or higher, wear protective clothing, and stay in the shade during peak UV hours. If you develop a severe sunburn or unusual skin rash, stop the medication and contact your doctor.
Tetralysal is generally not recommended for children under 8 years of age due to the risk of permanent tooth discoloration and effects on skeletal development. In children aged 8 to 12, it should only be used in exceptional circumstances under close medical supervision. For teenagers over 12 with acne, Tetralysal is commonly prescribed and considered safe when used as directed by a healthcare professional.
No, you must not take Tetralysal together with oral retinoids such as isotretinoin (Accutane/Roaccutane), acitretin, or etretinate. Both tetracyclines and retinoids can independently raise intracranial pressure, and combining them significantly increases the risk of pseudotumor cerebri (benign intracranial hypertension), a serious condition with symptoms including severe headache, visual disturbances, nausea, and vomiting. This combination is strictly contraindicated.
References
This article is based on the following peer-reviewed sources and international clinical guidelines:
- World Health Organization (WHO). Model List of Essential Medicines — 23rd List. Geneva: WHO; 2023.
- British Association of Dermatologists (BAD). Guidelines for the Management of Acne Vulgaris. British Journal of Dermatology. 2023.
- European Dermatology Forum (EDF). Nast A, et al. European Evidence-based (S3) Guideline for the Treatment of Acne — Update 2022. Journal of the European Academy of Dermatology and Venereology. 2023;37(Suppl 2):1-30.
- British National Formulary (BNF). Lymecycline Monograph. NICE Evidence Services. 2024.
- European Medicines Agency (EMA). Lymecycline — Summary of Product Characteristics. 2024.
- Garner SE, et al. Minocycline for acne vulgaris: efficacy and safety. Cochrane Database of Systematic Reviews. 2012;(8):CD002086.
- Simonart T, Dramaix M, De Maertelaer V. Efficacy of tetracyclines in the treatment of acne vulgaris: a review. British Journal of Dermatology. 2008;158(2):208-216.
- Zaenglein AL, et al. Guidelines of care for the management of acne vulgaris. Journal of the American Academy of Dermatology. 2016;74(5):945-973.
- Dréno B, et al. Antibiotic stewardship in dermatology: limiting antibiotic use in acne. European Journal of Dermatology. 2014;24(3):330-334.
- Galderma. Tetralysal (Lymecycline) — Patient Information Leaflet. 2021.
Medical Editorial Team
This article has been written and reviewed by the iMedic Medical Editorial Team, comprising licensed specialist physicians with expertise in clinical pharmacology, dermatology, and infectious disease medicine.
iMedic Medical Editorial Team — specialists in clinical pharmacology and evidence-based medicine with documented academic and clinical experience.
iMedic Medical Review Board — independent panel of board-certified physicians who review all content according to international guidelines (WHO, EMA, BNF, BAD).
GRADE methodology. Evidence Level 1A based on systematic reviews and international clinical guidelines. No commercial funding or pharmaceutical sponsorship.
All claims are supported by peer-reviewed references. Content is updated regularly to reflect the latest medical evidence and guideline revisions.