Cisapride
Contraindicated
Database
Possible rise in plasma levels of cisapride.
Exercise caution.
Drug reference
roxithromycin
Semisynthetic 14-membered macrolide antibiotic · Antibacterial
START
150 mg PO twice daily before food for 5–10 days
TYPICAL MAX
300 mg/day
STOP IF
Hepatitis, severe rash, or significant QT prolongation
WATCH
LFTs, ECG if QT-drug co-use, GI tolerance
CDSCO approvedATC J01FA06
KDIGO 2024 + manufacturer label
- ONSET
- 1h · absorption
- PEAK
- 2h · Tmax
- t½
- 12h · t½
- DURATION
- 12h · twice-daily
EXCRETION
Mainly faecal; minor renal
route + CYP
INTERACTIONS
2 major
incl. contraindicated
PREGNANCY
Use only if clearly needed; macrolide class generally acceptable.
FDA category + note
Top interactionssee all 6 →
- CisaprideContraindicatedDatabase
- Ergot AlkaloidsContraindicatedDatabaseKimi deep-research + Cla
Mechanism
Binds the bacterial 50S ribosomal subunit, inhibiting protein synthesis; bacteriostatic against Gram-positive cocci, atypicals (Mycoplasma, Chlamydia, Legionella) and some Gram-negatives.
Indications
Respiratory tract infections (pharyngitis, tonsillitis, bronchitis, pneumonia)Skin / soft-tissue infectionsGenital infections (Chlamydia, non-gonococcal urethritis)
Dosing
- Adult
- 150 mg PO twice daily OR 300 mg once daily for 5–10 days; take 15 min before food.
- Pediatric
- 5–8 mg/kg/day in 1–2 divided doses.
- Renal adjustment
- Caution in severe impairment; usually no fixed adjustment.
- Hepatic adjustment
- Reduce dose / extend interval in significant hepatic impairment.
- Geriatric
- Standard; monitor.
- Max dose
- 300 mg/day
Pharmacokinetics
Onset
Antibacterial effect over hours
Peak effect
~2 h (Tmax)
Duration
~12 h (twice-daily)
Half-life
~12 h
Bioavailability
~50% (better fasting)
Protein binding
~96%
Metabolism
Minimal hepatic
Excretion
Mainly faecal; minor renal
Contraindications
- Macrolide hypersensitivity
- Concomitant ergot alkaloids
- Caution: QT prolongation, hepatic impairment
Side effects
Common
Nausea/vomitingAbdominal painDiarrhoeaHeadacheRash
Serious
- QT prolongation (less than erythromycin/clarithromycin)
- Hepatotoxicity (cholestatic)
- Severe hypersensitivity / SJS
- C. difficile colitis
Pregnancy & lactation
Pregnancy
Use only if clearly needed; macrolide class generally acceptable.
Lactation
Small amounts in milk; generally compatible.
Drug interactions
Ergot Alkaloids
Contraindicated
Database
Reduced ergot metabolism
Contraindicated
Source: Kimi deep-research + Cla
Terfenadine
Moderate
Textbook
Possible rise in plasma levels of terfenadine.
Exercise caution.
Source: KDT 7e · p754
Qt Prolonging Drugs
Moderate
Database
Additive QT (less than erythromycin)
Monitor ECG; avoid stacking
Source: Kimi deep-research + Cla
Theophylline
Moderate
Database
Macrolide-class inhibition / absorption changes
Monitor levels
Source: Kimi deep-research + Cla
Warfarin
Moderate
Database
Variable INR change
Monitor INR
Source: Kimi deep-research + Cla
6 additional unreviewed or low-confidence interactions hidden because their provenance or source detail is insufficient.
Related guidelines
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Textbook-sourced·Sources: KD Tripathi 7e·Updated: 2026-05-20·Cockpit curated: 2026-05-20