Cyclox (Cyclacillin): Uses, Dosage, and Side Effects

Cyclox (cyclacillin) is a penicillinase-resistant penicillin antibiotic used for infections caused by susceptible Gram-positive bacteria, notably Staphylococcus aureus (including some penicillinase-producing strains).

Indications

• Skin and soft tissue infections: cellulitis, abscesses, wound infections, impetigo.
• Bone and joint infections: osteomyelitis, septic arthritis.
• Respiratory tract infections: pneumonia, bronchitis (when Staph suspected).
• Urinary tract infections (limited use).
• Gonorrhea (historically; now resistant strains prevalent).

Typical Adult Dose

250–500 mg every 6 hours IV/IM; oral forms less common. Duration: 7–14 days depending on infection.

Side Effects

Hypersensitivity (rash, anaphylaxis), GI upset, hepatotoxicity (rare), neutropenia (prolonged use), C. difficile colitis. Adjust dose in renal impairment.

Note: Cyclacillin is less commonly used today due to broader-spectrum alternatives. Always follow prescriber instructions.