Refractory Stable Angina Pregnancy: Limited data in pregnant women; animal studies showed embryo toxicity and the potential risk for humans is unknown — should not be used during pregnancy unless clearly necessary. Should not be used during breast-feeding (excretion in human milk unknown; excreted in rat milk). No adverse effects on fertility in animals; effect on human fertility unknown.

Ranolazine

Brand names: Ranexa

Ranolazine is an add-on anti-anginal for chronic stable angina, used when symptoms are inadequately controlled by, or the patient cannot tolerate, first-line therapy.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: Initially 375 mg (prolonged-release tablets)

Route: Oral — tablets should be swallowed whole and not crushed, broken or chewed; may be taken with or without food

Frequency: Twice daily; after 2–4 weeks titrate to 500 mg twice daily and, according to response, further to the recommended maximum of 750 mg twice daily

Max: 750 mg twice daily

Available as 375 mg, 500 mg and 750 mg prolonged-release tablets. If a patient experiences treatment-related adverse events (e.g. dizziness, nausea or vomiting), down-titration to 500 mg or 375 mg twice daily may be required; if symptoms do not resolve after dose reduction, treatment should be discontinued. Careful dose titration is recommended with moderate CYP3A4 inhibitors (e.g. diltiazem, fluconazole, erythromycin) or P-gp inhibitors (e.g. verapamil, ciclosporin); concomitant potent CYP3A4 inhibitors are contraindicated. Careful titration in mild hepatic impairment (contraindicated in moderate or severe hepatic impairment), in the elderly, in patients of low weight (60 kg or less) and in moderate to severe congestive heart failure (NYHA Class III–IV). Should not be used with CYP3A4 inducers (rifampicin, phenytoin, phenobarbital, carbamazepine, St John's Wort) — expected lack of efficacy. Paediatric population: safety and efficacy in children below the age of 18 years have not been established; no data are available. NOTE: the extracted SPC text has lost some '<' symbols (e.g. severe renal impairment appears as 'creatinine clearance 30 ml/min', meaning below 30 ml/min) — clinician to verify thresholds against the SPC.

Dose adjustments

Renal

Careful dose titration in mild to moderate renal impairment (creatinine clearance 30–80 ml/min); contraindicated in severe renal impairment (creatinine clearance below 30 ml/min — source text renders as '30 ml/min'). Renal function decreases with age, so check renal function at regular intervals during treatment.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

US labelling (FDA)

Reference — US labelling, may differ from UK

500 mg twice daily and increase to 1000 mg twice daily, based on clinical symptoms ( 2.1 ) 2.1 Dosing Information Initiate ranolazine extended-release tablet dosing at 500 mg twice daily and increase to 1000 mg twice daily, as needed, based on clinical symptoms. Take ranolazine extended-release tablet with or without meals. Swallow ranolazine extended-release tablet whole; do not crush, break, or chew. The maximum recommended daily dose of ranolazine extended-release tablet is 1000 mg twice daily. If a dose of ranolazine extended-release tablet is missed, take the prescribed dose at the next scheduled time; do not double the next dose. 2.2 Dose Adjustments in Specific Populations Dose …

Source: US FDA prescribing information (openFDA / DailyMed), label dated 2026-01-29. Accessed 2026-06-12. US dosing and indications can differ from UK practice — use UK sources for prescribing decisions.

Contraindications

Hypersensitivity to the active substance or any of the excipients
Severe renal impairment (creatinine clearance below 30 ml/min — source text renders as '30 ml/min')
Moderate or severe hepatic impairment
Concomitant administration of potent CYP3A4 inhibitors (e.g. itraconazole, ketoconazole, voriconazole, posaconazole, HIV protease inhibitors, clarithromycin, telithromycin, nefazodone)
Concomitant administration of Class Ia (e.g. quinidine) or Class III (e.g. dofetilide, sotalol) antiarrhythmics other than amiodarone

Side effects

Dizziness and headache (common)
Constipation, vomiting, nausea (common)
Asthenia (common)
Uncommon: hypotension, hot flush, syncope, somnolence, tremor, blurred vision, peripheral oedema, fatigue
Uncommon: prolonged QT corrected interval, increased blood creatinine and blood urea; rare acute renal failure

Interactions

Potent CYP3A4 inhibitors — contraindicated (itraconazole, ketoconazole, voriconazole, posaconazole, HIV protease inhibitors, clarithromycin, telithromycin, nefazodone)
Moderate CYP3A4 inhibitors (diltiazem, fluconazole, erythromycin) — careful dose titration recommended (US label: limit ranolazine to 500 mg twice daily)
P-gp inhibitors (verapamil, ciclosporin) — careful dose titration recommended; ranolazine exposure increased
CYP3A4 inducers (rifampicin, phenytoin, phenobarbital, carbamazepine, St John's Wort) — should not be used; expected lack of efficacy
Class Ia (quinidine) or Class III (dofetilide, sotalol) antiarrhythmics other than amiodarone — contraindicated; caution with other QTc-prolonging drugs
US label additions: limit simvastatin to 20 mg with ranolazine; limit metformin to 1700 mg daily with ranolazine 1000 mg twice daily; doses of P-gp-transported drugs (e.g. digoxin) or CYP2D6 substrates (e.g. tricyclic antidepressants) may need reduction

Clinical monograph

How it works

It inhibits the late inward sodium current in cardiac myocytes, reducing intracellular sodium and calcium overload and so improving myocardial relaxation and oxygen efficiency, with little effect on heart rate or blood pressure.

Prescribing in practice

It prolongs the QT interval, so avoid combining with other QT-prolonging drugs and use caution in patients at risk of QT prolongation.
It is a CYP3A4 substrate with many interactions; avoid strong CYP3A4 inhibitors and review concomitant medicines before starting.
Use is restricted or contraindicated in significant renal or hepatic impairment, so check renal and liver function before initiation.

Monitoring

Review renal and hepatic function and concurrent medicines before and during treatment; consider ECG monitoring of the QT interval where clinically indicated.

Counselling the patient

Tell any prescriber or pharmacist you take ranolazine before starting new medicines, as interactions are common.
Avoid grapefruit juice, which can raise the drug level.
Report palpitations, fainting or dizziness.

Evidence & guidelines

Recommended as an add-on option for stable angina when first-line drugs are insufficient or not tolerated (NICE NG185).

Reference: MERLIN-TIMI 36 Trial (Morrow et al. JAMA 2007); ESC Stable CAD Guidelines 2019; NICE CG126; SPC Ranexa; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways