Qt Prolonging Drugs
Severe
Database
Additive QT effect
Avoid combination; ECG monitoring
Source: Kimi deep-research + Cla
Drug reference
ketanserin
5-HT2A / α1-adrenergic receptor antagonist (antihypertensive) · Antihypertensive (selective 5-HT2 receptor blocker), Vasospastic conditions (Raynaud's disease), 5-HT2 receptor blocker (antihypertensive), Selective 5-HT2 receptor blocker (vasospastic conditions (Ra
START
20 mg PO twice daily
TYPICAL MAX
80 mg/day (40 mg twice daily)
STOP IF
QT prolongation / arrhythmia or severe hypotension
WATCH
BP, ECG (QT) if at-risk, electrolytes
CDSCO approvedATC C02KD01
KDIGO 2024 + manufacturer label
- ONSET
- 30min · absorption
- PEAK
- 1h · Tmax
- t½
- 14h · t½
- DURATION
- 12h · twice-daily
EXCRETION
Renal/faecal — metabolites
route + CYP
INTERACTIONS
1 major
SEVERE in our sources
PREGNANCY
Limited data; use only if benefit outweighs risk.
FDA category + note
Top interactionssee all 5 →
- Qt Prolonging DrugsSevereDatabaseKimi deep-research + Cla
Mechanism
Selective antagonist at serotonin 5-HT2A and α1-adrenergic receptors causing arteriolar vasodilation and reduced peripheral resistance; minimal effect on cardiac output or reflex tachycardia.
Indications
Hypertension (regions where licensed; not US/UK)Raynaud phenomenon (off-label)Carcinoid syndrome (selected, off-label)
Dosing
- Adult
- 20 mg PO twice daily, titrate every 4 weeks to 40 mg twice daily.
- Pediatric
- Not established.
- Renal adjustment
- Caution in severe impairment.
- Hepatic adjustment
- Reduce dose in significant hepatic impairment.
- Geriatric
- Start 10 mg twice daily; postural hypotension risk.
- Max dose
- 80 mg/day (40 mg twice daily)
Pharmacokinetics
Onset
BP effect within hours
Peak effect
~1 h (Tmax)
Duration
~12 h (twice-daily)
Half-life
~10–18 h
Bioavailability
~50%
Protein binding
~95%
Metabolism
Hepatic
Excretion
Renal/faecal (metabolites)
Contraindications
- Severe heart failure
- QT prolongation / proarrhythmia risk factors
- Hypersensitivity
Side effects
Common
DizzinessDrowsinessHeadacheDry mouthFatigue
Serious
- QT prolongation / arrhythmia
- Severe hypotension
- Serious skin reactions (rare)
Pregnancy & lactation
Pregnancy
Limited data; use only if benefit outweighs risk.
Lactation
Limited data; caution.
Drug interactions
Cns Depressants
Moderate
Database
Additive sedation
Counsel
Source: Kimi deep-research + Cla
Diuretics
Moderate
Database
Hypokalaemia-aggravated QT
Maintain K/Mg; monitor ECG
Source: Kimi deep-research + Cla
Other Antihypertensives
Moderate
Database
Additive BP lowering
Monitor BP
Source: Kimi deep-research + Cla
Serotonergic Drugs
Mild
Database
Pharmacologic 5-HT2A antagonism (no syndrome)
Routine monitoring
Source: Kimi deep-research + Cla
Related guidelines
Beta-blockers in hypertension
MOHFW · Cardiology · 2024
Acute coronary syndrome in chronic kidney disease
CSI · Cardiology · 2020
Hypertension in adults
ICMR · Cardiology · 2019
Empirical antimicrobial use in common syndromes
ICMR · Infectious Diseases · 2019
Hypertension in diabetes
MOHFW · Endocrinology · 2024
Ask House about ketanserin
Continue into a citation-backed clinical answer with the drug context already attached.
Sources: KD Tripathi 7e·Verified: 2026-05-20 · House clinical team·Cockpit curated: 2026-05-20