Tedizolid

Tedizolid is a newer oxazolidinone licensed for acute bacterial skin and skin structure infection as a once-daily 6-day course. It has less myelosuppression and weaker monoamine oxidase inhibition than linezolid, but data beyond 6 days are limited. It is a reserve drug with little availability in East Africa.

Classification. Oxazolidinone.

Mechanism. Binds the 23S rRNA of the 50S ribosomal subunit and blocks protein synthesis; bacteriostatic.

Spectrum. MRSA, MSSA, streptococci, vancomycin-resistant enterococci and linezolid-resistant strains that carry the cfr gene (in part). Not active against Enterobacterales or Pseudomonas.

Pharmacokinetics. Prodrug (tedizolid phosphate) converted rapidly to tedizolid. Oral bioavailability about 91%. Half-life about 12 hours. Protein binding 70 to 90%. Mainly hepatic conjugation with faecal excretion.

Fixed dose; no loading dose.

Adults and children 12 years and over. - Acute bacterial skin and skin structure infection: 200 mg orally or IV once daily for 6 days. - Off-label (specialist): bone and joint infection and nontuberculous mycobacterial infection, 200 mg once daily as part of a multidrug regimen for prolonged courses, with monitoring.

Children under 12 years. Not established.

Alternatives. Linezolid, doxycycline, clindamycin, trimethoprim sulfamethoxazole, vancomycin.

Contraindications. Hypersensitivity to tedizolid.

Adverse effects. Nausea, headache, diarrhoea, vomiting, dizziness. Serious: thrombocytopenia (less than linezolid), Clostridioides difficile infection, peripheral and optic neuropathy (prolonged use), hypersensitivity.

Interactions. Serotonergic drugs and monoamine oxidase inhibitors (caution though weaker than linezolid); breast cancer resistance protein substrates (for example rosuvastatin, methotrexate) may rise in level.

Common prescribing errors. Using it for more than 6 days without specialist input, treating non-skin infection without evidence, and omitting a medication review for serotonergic drugs.

Special groups. - Pregnancy: avoid unless essential. Breastfeeding: avoid. - Older adults: no adjustment. - Kidney impairment: no adjustment, including haemodialysis. - Liver impairment: no adjustment. - Region: not generally available in East Africa.

Preparation. Oral with or without food. IV: reconstitute 200 mg vial with 4 mL sterile water, dilute in 250 mL of 0.9% sodium chloride and infuse over 1 hour; do not use Hartmann solution or other additives.

Baseline and monitoring. - Baseline: full blood count, medication review, vision history. - During treatment: full blood count weekly if used for over 6 days; neuropathy and visual review in prolonged use.

Stop rules. Stop for severe cytopenia, visual loss, severe neuropathy or hypersensitivity.

Referral and escalation. Infectious diseases consultation for any use beyond 6 days or beyond skin infection.