Meds and you

Updated 11 February 2013


Lymecycline is a broad-spectrum antibiotic that is effective in treating a variety of bacterial infections.


Lymecycline is the active ingredient of Tetralysal.

General information

Lymecycline is a broad-spectrum antibiotic that is effective in treating a variety of bacterial infections. It is frequently prescribed to treat infections of the urinary, respiratory and gastrointestinal tracts, as well as infections of the skin. It is also used to treat certain sexually transmitted infections caused by organisms that are susceptible to lymecycline.

It is, however, most often used for the long-term treatment of acne.

It is important to note that this medication is only effective against bacterial infections - if your infection is the result of a viral or fungal infection, it will be ineffective.

Antibiotic resistance (that is, when bacteria develop the ability to defend themselves against the effect of an antibiotic) occurs frequently with many antibiotics. This most often occurs when patients do not complete the prescribed course in full or when antibiotics are used for non-bacterial infections such as cold and flu.

The absorption of lymecycline is impaired by food and it is recommended that the drug be taken at least one hour before or two hours after a meal. Antacids, milk and milk products and iron supplements should not be taken within two hours of a lymecycline dose as it may reduce the absorption, and thus the effect, of the antibiotic.

Lymecycline combines with calcium in the body and is deposited in the developing and growing bones and teeth of unborn babies and growing children. This may result in yellow-brown staining of both milk and permanent teeth, and retardation of bone growth. Lymecycline should therefore not be given to children under the age of 12, and pregnant or breastfeeding women.

An increased incidence of an abnormal sunburn reaction in people taking lymecycline has also been noted.

How does lymecycline work?

Tetracycline antibiotics function by inhibiting bacterial protein synthesis. Hereby, it prevents bacteria to produce specific proteins essential for their survival.

Fast facts

Drug schedule: schedule 4

Available as : lymecycline is available as capsules

What does it do? lymecycline has an anti-bacterial effect

Overdose risk: low

Dependence risk: low

Is lymecycline available as a generic? no

Is lymecycline available on prescription only? yes

User information

Onset of effect: may take a few days for the full beneficial effect to be reached and several weeks in the case of acne

Duration of action: up to 24 hours

Dietary advice: milk and milk products should not be given within two hours of taking lymecycline; medication should be taken with plenty of water

Stopping this medicine: do not stop taking this medication until you have finished the course as prescribed by your doctor - infection may recur with premature discontinuation

Prolonged use: there is a slim risk of liver damage during prolonged use of the drug

Special precautions

Consult your doctor before using this drug if:

  • you have liver or kidney disease
  • you have systemic lupus erythematosus
  • you have myasthenia gravis
  • you are taking any other medication

Pregnancy: avoid. Potential risk to the foetus has been reported. Consult your doctor before use, or if you are planning to fall pregnant.

Breastfeeding: avoid. This medication is passed through breast milk and may affect your baby adversely. Consult your doctor before use.

Porphyria: avoid. This medication may cause serious adverse effects. Consult your doctor before use.

Infants and children: this medication is not intended for use in children under the age of 12.

Elderly: no special precautions need to be taken.

Driving and hazardous work: no special precautions need to be taken.

Alcohol: no special precautions need to be taken.

Possible side effects

Side effect


Consult your doctor



Only if severe

In all cases







discoloration of teeth






skin rash/ itch






visual disturbance




Drug interactions


reduced effect of antibiotic; take two hours apart


risk of warfarin toxicity

medication for epilepsy such as carbamazepine, phenobarbital and phenytoin

reduced effect of antibiotic


risk of ciclosporin toxicity

iron salts

reduced antibiotic effect; reduced iron absorption

oral contraceptives

contraceptive failure is possible; use alternative contraception

isotretinoin/ acitretin

raised intracranial pressure

sodium bicarbonate

increased pH and reduced antibiotic activity


may reduce effect of antibiotic; space at least two hours apart

Food interactions

Milk and milk products should not be given within two hours of taking lymecycline.

Disease interactions

Consult your doctor before using this drug if you have liver disease, systemic lupus erythematosus, porphyria or myasthenia gravis.

Overdose action

A small overdose is no cause for concern. In case of intentional large overdose, seek emergency medical attention.

Recommended dosage

Adults: 300mg twice a day


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