Tetracycline Antibiotic Pregnancy: Contraindicated in pregnancy and breast-feeding. Minocycline crosses the placenta and may cause foetal harm; tetracyclines given during tooth development (last half of pregnancy) may cause permanent tooth discolouration and enamel hypoplasia, and post-marketing reports include congenital abnormalities such as limb reduction. Permanent tooth discolouration may occur in the developing infant if taken while breast-feeding.

Minocycline

Brand names: Minocin, Aknemin

Minocycline is a tetracycline antibiotic used for moderate inflammatory acne. Other tetracyclines are often preferred because minocycline carries some distinctive and potentially serious adverse effects.

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: One 100 mg modified-release capsule every 24 hours

Route: Oral

Frequency: Every 24 hours (once daily)

UK SPC used is Acnamino MR 100 mg Capsules (acne). Duration: treatment of acne should be continued for a minimum of 6 weeks and, where possible, limited to a maximum of six months. If after six months there is no satisfactory response, discontinue and consider other therapies. If continued beyond six months, monitor at least three-monthly (including laboratory investigations) for signs and symptoms of hepatitis, systemic lupus erythematosus or unusual pigmentation. Paediatric: children over 12 years — one 100 mg capsule every 24 hours (same as adults); minocycline should NOT be used in children under 12 years of age. Elderly: dose selection should be cautious, reflecting the greater frequency of decreased hepatic, renal or cardiac function and of concomitant disease or other drug therapy. Hepatic insufficiency: use with caution. Administration: swallow capsules whole with plenty of fluid while sitting or standing, to reduce the risk of oesophageal irritation and ulceration; absorption is not significantly impaired by food or moderate amounts of milk.

Dose adjustments

Renal

Minocycline must not be given to persons in renal failure (complete renal failure is a contraindication). In lesser degrees of renal insufficiency, reduction of dosage and monitoring of renal function may be required; no numeric adjustment is stated. Clinical studies showed no significant drug accumulation in renal impairment at recommended doses, but in significantly impaired renal function higher serum tetracycline levels may lead to uraemia, hyperphosphataemia, acidosis and possible liver toxicity.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

US labelling (FDA)

Reference — US labelling, may differ from UK

DOSAGE AND ADMINISTRATION THE USUAL DOSAGE AND FREQUENCY OF ADMINISTRATION OF MINOCYCLINE DIFFER FROM THAT OF THE OTHER TETRACYCLINES. EXCEEDING THE RECOMMENDED DOSAGE MAY RESULT IN AN INCREASED INCIDENCE OF SIDE EFFECTS. Minocycline hydrochloride capsules may be taken with or without food (see CLINICAL PHARMACOLOGY ). Ingestion of adequate amounts of fluids along with capsule and tablet forms of drugs in the tetracycline-class is recommended to reduce the risk of esophageal irritation and ulceration. The capsules should be swallowed whole. For Pediatric Patients above 8 Years of Age Usual pediatric dose: 4 mg/kg initially followed by 2 mg/kg every 12 hours, not to exceed the usual adult …

Source: US FDA prescribing information (openFDA / DailyMed), label dated 2026-01-01. Accessed 2026-06-12. US dosing and indications can differ from UK practice — use UK sources for prescribing decisions.

Contraindications

Hypersensitivity to minocycline, other tetracyclines, or any of the excipients
Pregnancy and lactation
Children under the age of 12 years
Complete renal failure

Side effects

Dizziness / light-headedness (common); headache, paraesthesia, vertigo and intracranial hypertension (rare)
Hypersensitivity and skin reactions — rash, urticaria, pruritus, photosensitivity, hyperpigmentation of skin, erythema multiforme (rare); Stevens-Johnson syndrome, toxic epidermal necrolysis, angioedema, exfoliative dermatitis (very rare); anaphylaxis/anaphylactoid reaction including shock and fatalities (rare)
Hepatobiliary — raised liver enzymes, hepatitis, autoimmune toxicity (rare); hepatic cholestasis, hepatic failure including fatalities, jaundice (very rare)
Lupus-like syndrome, arthralgia, myalgia (rare); new or worsened systemic lupus erythematosus (very rare)
Gastrointestinal — diarrhoea, nausea, vomiting, stomatitis, tooth discolouration (rare); oesophagitis and oesophageal ulceration, pancreatitis, pseudomembranous colitis (very rare)
Haematological — eosinophilia, leucopenia, neutropenia, thrombocytopenia (rare); haemolytic anaemia, pancytopenia (very rare)

Interactions

Anticoagulants — tetracyclines depress plasma prothrombin activity; downward adjustment of anticoagulant dosage may be required
Penicillins — bacteriostatic drugs may interfere with the bactericidal action of penicillin; avoid concurrent use
Antacids containing aluminium, calcium or magnesium, and iron-containing preparations — impair absorption of tetracyclines
Oral contraceptives — concurrent use may render oral contraceptives less effective (SPC §4.4 also warns that diarrhoea or breakthrough bleeding may signal contraceptive failure)
Isotretinoin — avoid shortly before, during and shortly after minocycline therapy; each drug alone has been associated with pseudotumor cerebri
Ergot alkaloids or their derivatives — increased risk of ergotism with tetracyclines
NOTE: the UK SPC §4.5 was not captured in this bundle; the interactions above are from the US labelling and should be checked against the UK SPC

Clinical monograph

How it works

It inhibits bacterial protein synthesis by binding the 30S ribosomal subunit; in acne it both suppresses Cutibacterium acnes and has anti-inflammatory effects on the pilosebaceous unit.

Prescribing in practice

Unlike other acne antibiotics it can cause a drug-induced lupus-like syndrome, irreversible blue-grey pigmentation of skin, mucosa and scars, and benign intracranial hypertension — stop it and reassess if a lupus-like illness, new pigmentation, or headache with visual disturbance develops, and do not combine it with oral retinoids (additive intracranial-hypertension risk).
It is contraindicated in pregnancy and breastfeeding and in children under 12 years, because tetracyclines deposit in developing teeth and bone and cause permanent tooth discolouration.
It can cause photosensitivity and, like other tetracyclines, hepatotoxicity; reserve it and review the need to continue, in line with local antimicrobial guidance.

Monitoring

No routine blood monitoring is needed for short courses, but reassess periodically on prolonged treatment and investigate promptly if features of lupus-like syndrome, hepatitis or raised intracranial pressure appear.

Counselling the patient

Report a persistent headache (especially with blurred or double vision), joint pains with feeling unwell, or new darkening of the skin, gums or scars.
Use sun protection, as your skin may burn more easily.
Take it with a full glass of water and tell your prescriber if you might be pregnant.

Evidence & guidelines

An option for inflammatory acne, but UK acne guidance generally favours other tetracyclines (such as lymecycline or doxycycline) given minocycline's distinctive adverse-effect profile.

Reference: BAD Acne Guidelines (2017, updated 2021); BAD Rosacea Guidelines (2021); MHRA minocycline drug-induced lupus warning; NICE CKS Acne Vulgaris; SPC Minocin MR; 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

Drugs

Pathways