Clinical beta
FMBM is currently in clinical beta. Content is for professional review/testing and must not replace local protocols, senior clinical judgment, or official prescribing references.
Drug Monograph
Clarithromycin
Macrolide (PO, IV)
Indication
H. pylori β’ CAP atypical β’ NTM β’ sinusitis selected
INDICATIONS (CORE USE)
H. pylori triple/quad therapy; atypical coverage; **strong CYP3A inhibitor** β statins, colchicine, DOAC interactions.
ADULT DOSE (STANDARD)
500 mg PO BID; XL 1 g daily (formulation dependent); H. pylori regimens 500 mg BID
MAX DOSE
1 g/day XL vs 1 g/day divided immediate per product
Route
PO, IV
PEDIATRIC DOSE
7.5 mg/kg PO BID max 500 mg BID
Must-not-miss safety points
Major warning
- QT prolongation - **CYP3A interactions** β colchicine contraindicated with clarithromycin in many renal scenarios; simvastatin contraindicated - Hepatotoxicity - Macrolide resistance S. pneumoniae in some regions
USE IF: H. pylori regimen, atypical coverage when azithro not chosen, NTM specialist. AVOID IF: On simvastatin/colchicine without hold; long QT risk.
Primary
Secondary
Other
STANDARD (ADULT PO)
500 mg PO q12h Γ 7β14d (infection) OR 500 mg BID Γ 14d (H. pylori component)
ADULT DOSE
500 mg PO BID 7β14d infections; H. pylori 14d triple therapy common
PEDIATRIC DOSE
Suspension per mg/kg.
MAX DOSE
Follow formulation max daily.
Practical Note
XL vs immediate release not interchangeable mg-for-mg schedule.
Clinical warnings
Adverse effects
Pediatrics
7.5 mg/kg PO BID max 500 mg BID
Pregnancy
Animal data β human use if benefit
Lactation
excreted β caution.
Renal impairment
CrCl <30 β reduce dose / extend interval per label for tablet **CrCl scaffold (FMBM β titrate to FDA/SFDA label + institutional pharmacy nomogram):** - **CrCl β₯50** β standard per agent (azithro PO often unchanged) - **CrCl 10β50** β clarithro/erythro β check label for interval/dose; azithro usually minimal change - **CrCl <10** β extend interval or reduce dose per label (Zmax / IV forms β **verify product**)
Hepatic impairment
Severe hepatic impairment β contraindicated IV; PO caution.
Elderly
QT + renal dosing + polypharmacy.
PO with food reduces GI upset; IV infusion rate per monograph.
Clinical Picture
**Life-threatening (first):** **torsades / polymorphic VT** (QT). **Secondary:** GI upset; hearing at extreme exposure.
Immediate Actions
Stop macrolide β ECG; K+/Mg2+ repletion; telemetry if symptomatic
Antidote
No specific antidote; treat complications (e.g. anaphylaxis β epinephrine per ACLS)
Decontamination
Recent large PO β charcoal if appropriate
Escalation
Torsades / unstable VT β **ICU** ACLS; magnesium per protocol; **severe renal failure with accumulation β consider HD** (erythromycin more than azithro) β pharmacy
Common mistakes, resistance logic, and bedside traps
**H. pylori** staple. **CYP3A sledgehammer** β simvastatin/colchicine nightmares. QT like other macrolides.
Stewardship: CAP β prefer beta-lactam backbone in many guidelines. NTM: always specialist + TDM sometimes. *Stewardship (all antimicrobials):* Empiric choice β syndrome severity + **local antibiogram**; shortest effective course.
Hepatic metabolism; CYP3A4 substrate/inhibitor; penetrates intracellular pathogens.
50S macrolide β bacteriostatic.
Saudi Arabia
Klacid, Biaxin
Global
(placeholder β verify local formulary)
Common trade names are curated examples only β formulations and availability vary. Verify the exact product name with your local pharmacy and national regulator before prescribing or dispensing.
Saudi Arabia
International