Lymecycline

Generic Name

Lymecycline

Chemical Class

Tetracycline-class broad-spectrum antibiotic

It is the ethylenediamine salt of tetracycline, more water-soluble and better absorbed orally than tetracycline itself

Brand Names

Tetralysal

Lymecycline Actavis

Lymecycline Almus

Lymecycline Sandoz

Lymecycline Tillomed

Other international brands include Gramalyn, Mekocycline, and Demeclocine

Drug Class

Antibacterial

Tetracycline-class antibiotic

Bacteriostatic protein synthesis inhibitor

Mechanism of Action

Lymecycline inhibits bacterial protein synthesis by reversibly binding to the 30S ribosomal subunit

This blocks the attachment of aminoacyl-tRNA to the mRNA-ribosome complex

The result is inhibition of bacterial protein synthesis and suppression of bacterial growth

It exhibits bacteriostatic activity against many Gram-positive and Gram-negative organisms

Also effective against some atypical organisms like Chlamydia, Mycoplasma, Rickettsia, and Propionibacterium acnes (now Cutibacterium acnes)

Spectrum of Activity

Gram-positive bacteria: Staphylococcus aureus (including some MRSA), Streptococcus spp.

Gram-negative bacteria: Haemophilus influenzae, Escherichia coli, Neisseria gonorrhoeae, Yersinia pestis

Atypical: Chlamydia trachomatis, Mycoplasma pneumoniae, Rickettsia spp., Borrelia burgdorferi

Anaerobes: limited activity

Protozoa: some efficacy against Plasmodium spp.

Resistance may be mediated via efflux pumps or ribosomal protection proteins

Indications

Licensed Uses

Acne vulgaris (moderate to severe inflammatory acne)

Respiratory tract infections

Urinary tract infections

Sexually transmitted infections (e.g., Chlamydia)

Rickettsial infections

Prophylaxis of malaria (off-label or in select guidelines)

Skin and soft tissue infections

Brucellosis (in combination therapy)

Off-Label Uses

Rosacea (anti-inflammatory, not curative)

Lyme disease (alternative when doxycycline is unavailable)

Pelvic inflammatory disease (part of combination therapy)

Traveler’s diarrhea (less commonly than doxycycline)

Dosage and Administration

Standard Dose (Adults and Children ≥12 years)

300 mg to 408 mg once daily orally

Often 408 mg (equivalent to ~300 mg tetracycline base) is used for acne

Alternative Dosage in Infections

408 mg twice daily in severe infections (based on clinical need)

Duration depends on the site and severity of infection

Acne vulgaris

408 mg once daily for 8–12 weeks

May be extended up to 6 months depending on response and physician discretion

Topical agents (e.g., benzoyl peroxide, retinoids) often co-prescribed

Pediatric Use

Not recommended for children under 12 years of age

Contraindicated due to risk of permanent tooth discoloration and enamel hypoplasia

Renal Impairment

Dose adjustment generally not required in mild-moderate impairment

Caution advised in severe impairment due to tetracycline class renal handling

Administration Notes

Take with a full glass of water to prevent esophageal irritation

Preferably taken on an empty stomach, but can be taken with food if gastric upset occurs

Avoid taking concurrently with milk, antacids, iron, calcium, or magnesium supplements (reduced absorption)

Pharmacokinetics

Absorption

Rapid oral absorption

Bioavailability: ~100%

Peak plasma concentration: 2–3 hours post-dose

Distribution

Widely distributed throughout body tissues

Crosses placenta and enters breast milk

Crosses blood-brain barrier (low CNS levels)

Metabolism

Minimal hepatic metabolism

Elimination

Excreted primarily unchanged in urine and feces

Elimination half-life: ~8–10 hours

Prolonged in renal impairment

Contraindications

Hypersensitivity to tetracyclines

Children under 12 years

Pregnancy (due to risk of fetal teeth and bone development issues)

Breastfeeding (excreted in breast milk and affects dental development)

Severe hepatic failure (use with caution)

Warnings and Precautions

Photosensitivity

Patients may develop exaggerated sunburn reactions

Advise to avoid direct sunlight or tanning beds

Use protective clothing and broad-spectrum sunscreen

Esophageal Irritation and Ulceration

Instruct patients to take with sufficient water and remain upright for at least 30 minutes

Superinfections

Prolonged use may cause fungal or resistant bacterial overgrowth

Candidiasis, enterocolitis, or Clostridioides difficile-associated diarrhea (CDAD) possible

Hepatotoxicity

Rarely causes hepatic dysfunction

Monitor liver function tests in prolonged use or pre-existing liver disease

Benign Intracranial Hypertension (Pseudotumor Cerebri)

Occurs mostly in females of childbearing age

Symptoms: headache, visual changes, papilledema

Discontinue if suspected

Skeletal Effects

Binds to calcium, may affect fetal bone growth or infant tooth development

Avoid during pregnancy and lactation

Pregnancy and Lactation

Pregnancy

Category D (US)

Avoid throughout pregnancy

Risk of permanent tooth discoloration and inhibition of bone growth

Lactation

Excreted in breast milk

Not recommended due to risk of dental enamel hypoplasia and growth inhibition in the infant

Adverse Effects

Very Common

Nausea

Abdominal pain

Headache

Common

Vomiting

Diarrhea

Photosensitivity

Dizziness

Rash

Fatigue

Less Common

Benign intracranial hypertension

Esophagitis

Candidiasis (oral or vaginal)

Liver enzyme elevation

Skin hyperpigmentation

Rare

Hypersensitivity reactions (urticaria, angioedema, anaphylaxis)

Erythema multiforme, Stevens-Johnson syndrome

Hepatitis

Renal impairment (Fanconi syndrome in outdated tetracyclines)

Pancreatitis

Overdose

Symptoms include GI irritation, vomiting, and rarely liver or renal injury

Treatment is supportive; no specific antidote

Hemodialysis not effective due to high protein binding

Drug Interactions

Cation-containing compounds (calcium, magnesium, aluminum, iron, zinc)

Chelation reduces lymecycline absorption

Separate administration by at least 2 hours

Oral contraceptives

Tetracyclines may reduce effectiveness through gut flora disruption

Advise additional contraceptive methods during treatment

Anticoagulants (e.g., warfarin)

Potentiation of anticoagulant effect

Monitor INR closely

Retinoids (e.g., isotretinoin)

Increased risk of intracranial hypertension

Avoid concomitant use

Penicillins

Antagonistic antibacterial effect (tetracyclines are bacteriostatic, penicillins are bactericidal)

Avoid combining when treating serious infections

Methoxyflurane

Concurrent use may result in fatal nephrotoxicity

Contraindicated

Use in Special Populations

Children under 12 years

Contraindicated due to effects on teeth and bones

Elderly

No specific precautions

Use normal adult dose unless renal or hepatic impairment exists

Renal Impairment

Mild/moderate: no dose adjustment

Severe: use with caution; monitor renal function

Hepatic Impairment

Caution advised

Avoid in severe hepatic failure

Monitoring Parameters

Clinical response (improvement of acne or infection)

Signs of superinfection (e.g., candidiasis, diarrhea)

Liver and renal function if treatment exceeds 2–3 weeks

Signs of photosensitivity

Visual disturbances suggestive of intracranial hypertension

Comparative Pharmacology

Lymecycline vs Doxycycline

Doxycycline has longer half-life and once-daily dosing

Doxycycline more commonly used in systemic infections

Lymecycline is better tolerated in acne treatment with fewer GI side effects

Lymecycline vs Minocycline

Minocycline penetrates sebaceous glands better

Minocycline associated with more serious side effects (e.g., lupus-like syndrome, pigmentation)

Lymecycline preferred for tolerability

Lymecycline vs Tetracycline

Lymecycline has superior oral bioavailability and less frequent dosing

Better GI tolerance than tetracycline

Legal and Regulatory Status

Prescription-only medication in most countries

Not listed in WHO Model List of Essential Medicines

Included in several national formularies for acne and bacterial infections