BMA Concise Guide to Medicine & Drugs


Brand name Tetralysal 300

Used in the following combined preparation Deteclo


Drug group Tetracycline antibiotic

Overdose danger rating Low

Dependence rating Low

Prescription needed Yes

Available as generic Yes


Tetracycline and lymecycline are tetracycline antibiotics, once a very widely used class of antibiotics. The development of drug-resistant bacteria has, however, reduced tetracyclines’ effectiveness in many types of infection. Tetracycline and lymecycline are commonly used to treat acne and are still used for the treatment of chronic bronchitis, destructive forms of dental disease, and certain chest and genital infections due to mycoplasma organisms. They remain the treatment of choice for infections due to Chlamydia and Rickettsia.

Taken by mouth, these drugs can sometimes cause nausea, vomiting, and diarrhoea. Tetracyclines may discolour developing teeth if taken by children or by the mother during pregnancy. People with poor kidney function are not prescribed tetracycline/lymecycline because they can cause further deterioration.


Your drug prescription is tailored for you. Do not alter your dosage without checking with your doctor.

How taken/used Tablets, capsules.

Frequency and timing of doses By mouth 2–4 x daily, at least 1 hour before or 2 hours after meals (tetracycline); 1–2 x daily (lymecycline). Always swallow doses with water.

Adult dosage range Infections 1–2g daily (tetracycline); 916–1,032mg daily (lymecycline). Acne 1g daily (tetracycline); 408mg daily (lymecycline).

Onset of effect 4–12 hours. Improvement in acne may not be noticed for up to 4 weeks.

Duration of action Up to 6 hours.

Diet advice Milk products should be avoided for 1 hour before and 2 hours after taking the drug.

Storage Keep in original container at room temperature out of the reach of children.

Missed dose Take as soon as you remember. If your next dose is due within 2 hours, take a single dose now and skip the next.

Stopping the drug Take the full course. Even if you feel better, the original infection may still be present and may recur if treatment is stopped too soon.

Exceeding the dose An occasional unintentional extra dose is unlikely to be a cause for concern. But if you notice any unusual symptoms, or if a large overdose has been taken, notify your doctor.


Swallowing difficulties and/or oesophageal irritation may occur if a dose is taken with insufficient water, and the medication may stick in your throat if you lie down immediately after taking it. Other common adverse effects include nausea, vomiting, and diarrhoea; discuss with your doctor if they are severe. More rarely, the drug may cause a rash (which may sometimes be light-sensitive) and itching; if these occur, you should stop taking the drug and consult your doctor. If jaundice, headache, or visual disturbances occur, you should stop taking the drug and contact your doctor immediately.


Iron may reduce the effectiveness of tetracycline/lymecycline.

Oral anticoagulants Tetracycline/lymecycline may increase the action of these drugs.

Retinoids may increase the adverse effects of tetracycline/lymecycline.

Diuretics These should not be used with lymecycline.

Oral contraceptives Tetracycline/lymecycline may reduce the effectiveness of oral contraceptives.

Antacids and milk These interfere with the absorption of tetracycline/lymecycline and may reduce their effectiveness. Doses should be separated by 1–2 hours.

Methotrexate Tetracycline may increase the risk of methotrexate toxicity.


Be sure to tell your doctor if:

· You have long-term liver or kidney problems.

· You have previously suffered an allergic reaction to a tetracycline antibiotic.

· You have myasthenia gravis, acute porphyria, or systemic lupus erythematosus.

· You are taking other medicines.

Pregnancy Not prescribed. May cause birth defects and may damage the teeth and bones of the developing baby as well as the mother’s liver. Discuss with your doctor.

Breast-feeding Not recommended. The drugs pass into the breast milk and may damage developing bones and discolour the baby’s teeth. Discuss with your doctor.

Infants and children Not recommended under 12 years. Reduced dose necessary in older children. May discolour developing teeth.

Over 60 No special problems.

Driving and hazardous work No known problems.

Alcohol No known problems.

How to take your tablets To prevent the medication from sticking in your throat, a small amount of water should be taken before, and a full glass of water taken after, each dose. Take this medication while sitting or standing and do not lie down immediately afterwards.


No problems expected.