Oral tetracycline antibiotic (anti-acne) Pregnancy: Should not be administered to pregnant women - tetracyclines readily cross the placental barrier and are selectively absorbed by developing bones and teeth, and may cause dental dyschromia and enamel hypoplasia. Should not be administered to breast-feeding women (tetracyclines are distributed into milk; risk of enamel hypoplasia or dental dyschromia in the infant). No data on the effect on fertility are available.

Lymecycline 408mg (Acne)

Brand names: Tetralysal 300

Lymecycline is an oral tetracycline-class antibiotic used as a systemic treatment for moderate-to-severe inflammatory acne.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: Acne (adults): 1 capsule (408 mg) daily; treatment should be continued for at least eight (8) weeks.

Route: Oral - capsules should always be taken with a glass of water

Frequency: Once daily

No maximum dose is stated for acne in the SPC, so no maxDose is given here; the acne posology is 408 mg once daily with no stated escalation. OTHER INDICATIONS (do NOT apply to this acne page): for other infections the usual dosage is one capsule (408 mg) twice a day, and where higher doses are required 3-4 capsules (1224 mg - 1632 mg) may be given over 24 hours; in the management of sexually transmitted disease both partners should be treated. Elderly: as for other tetracyclines, no specific dosage adjustment is required. Renal impairment: contraindicated in overt renal insufficiency. Hepatic impairment: use with caution - potential for accumulation with increased toxicity. PAEDIATRIC: safety and efficacy in children aged under 12 years have not been established and no data are available; for children over the age of 12 years the adult dosage may be given (no per-kg dose is stated); contraindicated in children less than 8 years. Verify any paediatric use against a children's formulary. Take with adequate fluid to avoid oesophageal irritation and ulceration; avoid direct sunlight and ultraviolet light during treatment and discontinue if erythematous cutaneous manifestations occur. SOURCE: UK SPC for 'Lymecycline 408 mg Capsules, hard'.

Dose adjustments

Renal

Contraindicated in patients with overt renal insufficiency; caution should be exercised if renal function is impaired.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

Hypersensitivity to the active substance or to any other tetracycline, or to any of the excipients
Overt renal insufficiency
Children less than 8 years of age (risk of permanent dental staining and enamel hypoplasia)
Concurrent treatment with oral retinoids

Side effects

Common: nausea, abdominal pain, diarrhoea
Common: headache; not known: dizziness, intracranial hypertension
Skin: erythematous rash, photosensitivity, pruritus, Stevens-Johnson syndrome (not known)
Hepatobiliary: jaundice, hepatitis, increased transaminases, alkaline phosphatase and bilirubin (not known)
Immune: anaphylactic reaction, hypersensitivity, urticaria, angioneurotic oedema (not known); also neutropenia and thrombocytopenia

Interactions

Iron preparations, antacids (magnesium/aluminium and calcium hydroxides, oxides, salts), cholestyramine, bismuth chelates, sucralfate and quinapril may decrease cycline absorption - these products should not be taken within two hours before or after lymecycline
Enzyme inducers such as barbiturates, carbamazepine and phenytoin may accelerate the decomposition of tetracycline through hepatic enzyme induction, decreasing its half-life
Lithium - combination with lymecycline may cause an increase in serum lithium levels
Oral retinoids and vitamin A above 10 000 IU/day - concomitant use should be avoided as this may increase the risk of benign intracranial hypertension
Anticoagulants - an increase in effect may occur with tetracyclines, with an increased risk of haemorrhage
Diuretics - concomitant use should be avoided
Milk: unlike earlier tetracyclines, absorption of lymecycline is not significantly impaired by moderate amounts of milk

Clinical monograph

How it works

It inhibits bacterial protein synthesis by binding the 30S ribosomal subunit and also has anti-inflammatory properties, reducing Cutibacterium acnes and inflammation within the pilosebaceous unit.

Prescribing in practice

Contraindicated in pregnancy, breastfeeding and in children under twelve because tetracyclines cause permanent tooth discolouration and affect bone development.
It can cause photosensitivity, so advise sun protection and avoidance of excessive UV exposure.
Absorption is reduced by calcium, iron, antacids and dairy, so separate dosing from these and review concurrent use of oral retinoids.

Monitoring

Monitoring is largely clinical over a defined treatment course, reviewing acne response and tolerability and watching for rare but serious reactions such as benign intracranial hypertension.

Counselling the patient

Do not take if you are or might become pregnant, and use reliable contraception.
Protect your skin from strong sunlight as this medicine can make you burn more easily.
Report severe headache with visual disturbance, which needs urgent assessment.

Evidence & guidelines

Oral tetracyclines such as lymecycline are recommended by NICE as a systemic option for moderate-to-severe acne, typically combined with a topical agent.

Reference: BAD Acne Guidelines 2021; NICE CG184; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways