Linezolid
Contraindicated
Database
Serotonin syndrome risk.
Contraindicated. Use alternative antibiotic.
Source: DDInter
Drug reference
Venlafaxine
Serotonin-norepinephrine reuptake inhibitor (SNRI) · Antidepressant
Also known as Venlafaxine Hydrochloride
START
37.5-75 mg/day; check baseline BP; screen for bipolar disorder and suicide risk; prefer XR formulation for adherence
TYPICAL MAX
225 mg/day (XR); 375 mg/day (IR)
STOP IF
Sustained hypertension (>180/110), serotonin syndrome, suicidal ideation, severe discontinuation symptoms
WATCH
BP at each visit (dose-dependent increase), mood/suicide risk (first 4 weeks), sodium (elderly), taper over >/=2 weeks
CDSCO approvedSchedule HATC N06AX16
KDIGO 2024 + manufacturer label
- ONSET
- 1.4h · absorption onset
- PEAK
- 5.5h · XR peak (venlafaxine)
- t½
- 8h · Combined effective half-life
- DURATION
- 1d · XR: 24-hour coverage
EXCRETION
Renal (87%, as ODV)
route + CYP
INTERACTIONS
12 major
incl. contraindicated
PREGNANCY
Avoid in third trimester; risk of neonatal discontinuation syndrome and PPHN; use with caution in first/second trimester
FDA category + note
Top interactionssee all 12 →
- LinezolidContraindicatedDatabaseDDInter
- MaoisContraindicatedDatabaseKimi deep-research + Cla
- AlfentanilSevereDatabaseDDInter
- AlmotriptanSevereDatabaseDDInter
Available in India
250 branded formulations and 27 fixed-dose combinations. Look up specific brands in the Drugs workspace.
Mechanism
Blocks reuptake of serotonin (5-HT) and norepinephrine (NE), with weak dopamine reuptake inhibition at higher doses. The dual mechanism enhances neurotransmission in descending pain inhibitory pathways and mood-regulating circuits. Minimal affinity for muscarinic, histaminergic, and alpha-adrenergic receptors.
Indications
Major depressive disorderGeneralized anxiety disorderPanic disorderSocial anxiety disorderNeuropathic pain (off-label)
Dosing
- Adult
- Start 37.5-75 mg/day in 2-3 divided doses or XR once daily; titrate by 75 mg every 4 days; usual 150-225 mg/day; max 375 mg/day (IR) or 225 mg/day (XR)
- Pediatric
- Not recommended under 18 years
- Renal adjustment
- eGFR 10-30: reduce dose by 25-50%; eGFR <10: reduce dose by 50%
- Hepatic adjustment
- Mild-moderate: reduce dose by 50%; Severe: avoid
- Geriatric
- Start 37.5 mg/day; titrate slowly; monitor for hyponatremia
- Max dose
- 375 mg/day (IR); 225 mg/day (XR)
Pharmacokinetics
Onset
Depression: 2-4 weeks; Anxiety: 2-6 weeks
Peak effect
IR: 2 hours; XR: 5.5 hours (venlafaxine), 8 hours (ODV)
Duration
IR: 8-12 hours; XR: 24 hours
Half-life
Venlafaxine: 5 hours; O-desmethylvenlafaxine (ODV): 11 hours
Bioavailability
45% (IR); ~85% of theoretical (XR)
Protein binding
Venlafaxine: 27%; ODV: 30%
Metabolism
Hepatic CYP2D6 (primary) to active metabolite ODV; also CYP3A4, CYP2C9, CYP2C19, CYP2B6
Excretion
Renal (87%, primarily as ODV); fecal (<5%)
Contraindications
- Concomitant MAOIs or within 14 days of MAOI discontinuation
- Uncontrolled narrow-angle glaucoma
- Severe renal impairment (eGFR <10)
- Severe hepatic impairment
Side effects
Common
NauseaHeadacheSomnolence or insomniaDizzinessDry mouthConstipationSweatingSexual dysfunctionLoss of appetiteElevated BP
Serious
- Suicidal ideation (<24 years, black box warning)
- Serotonin syndrome
- Hypertension (dose-related)
- Hyponatremia/SIADH
- Discontinuation syndrome (severe with abrupt cessation)
- Hepatotoxicity (rare)
- Mania induction (bipolar patients)
- Seizures (rare)
Pregnancy & lactation
Pregnancy
Avoid in third trimester; risk of neonatal discontinuation syndrome and PPHN; use with caution in first/second trimester
Lactation
Excreted in breast milk; ODV levels may be higher than maternal venlafaxine; use with caution
Drug interactions
Maois
Contraindicated
Database
Serotonin syndrome, hyperthermia, seizures, death; 14-day washout required
Never combine; 14-day gap between MAOI and venlafaxine
Source: Kimi deep-research + Cla
Alfentanil
Severe
Database
Drug interaction classified as: synergy
Source: DDInter
Almotriptan
Severe
Database
Drug interaction classified as: synergy
Source: DDInter
Amiodarone
Severe
Database
Drug interaction classified as: synergy.
Source: DDInter
Amisulpride
Severe
Database
Drug interaction classified as: synergy.
Source: DDInter
Amitriptyline
Severe
Database
Drug interaction classified as: synergy.
Source: DDInter
Amoxapine
Severe
Database
Drug interaction classified as: synergy
Source: DDInter
Amphetamine
Severe
Database
Drug interaction classified as: synergy.
Source: DDInter
Anagrelide
Severe
Database
Drug interaction classified as: synergy
Source: DDInter
Arsenic Trioxide
Severe
Database
Drug interaction classified as: synergy
Source: DDInter
Bedaquiline
Severe
Database
Drug interaction classified as: synergy
Source: DDInter
Related guidelines
Other Serotonin-norepinephrine reuptake inhibitor (SNRI) drugs
Ask House about Venlafaxine
Continue into a citation-backed clinical answer with the drug context already attached.
Sources: Goodman & Gilman 14e, Harrison 22e, Katzung, BNF·Verified: 2026-05-19 · House clinical team·Cockpit curated: 2026-05-19