Adrenaline
Severe
Textbook
Marked rise in BP.
Adrenaline should not be given to patients receiving β blockers.
Source: KDT 7e · p133
Drug reference
Timolol
Non-selective beta-adrenergic receptor antagonist (beta-blocker) · Antihypertensive
Also known as Timolol maleate, Timoptic, Betimol
START
Check HR (>60 bpm), BP, auscultate for wheeze/asthma, review cardiac history. Baseline ECG if cardiac disease.
TYPICAL MAX
Do not exceed 60mg/day oral. Watch for fatigue, depression, sexual dysfunction at higher doses.
STOP IF
HR <50 bpm, systolic BP <90 mmHg, new wheeze/bronchospasm, acute heart failure, syncope, severe depression.
WATCH
Diabetics—may mask hypoglycemia tremors. COPD/asthma—risk of bronchospasm even with ophthalmic (systemic absorption). Do not stop abruptly—rebound angina/arrhythmia risk.
CDSCO approvedJan AushadhiNPPA price-controlledATC C07AA06
KDIGO 2024 + manufacturer label
- ONSET
- 30min · Onset 30 min (ocular)
- PEAK
- 1.5h · Tmax ~1-2 hours
- t½
- 4h · t½ ~4 hours
- DURATION
- 12h · 12-24 hours
EXCRETION
Renal as metabolites (~80%)
route + CYP
INTERACTIONS
12 major
SEVERE in our sources
PREGNANCY
Small amounts cross placenta; may cause fetal bradycardia, hypoglycemia. Use only if benefit outweighs risk—prefer cardioselective beta-blockers in pregnancy.
FDA category + note
Top interactionssee all 12 →
- AdrenalineSevereTextbookKDT 7e · p133
- AmilorideSevereTextbookKDT 7e
- SofosbuvirSevereTextbookHarrison 22e · unknown
- AminophyllineSevereDatabaseDDInter
Available in India
82 branded formulations and 65 fixed-dose combinations. Look up specific brands in the Drugs workspace.
Jan Aushadhi — generic available at GoI pharmacies
Mechanism
Non-selective competitive antagonism of beta-1 and beta-2 adrenergic receptors; reduces heart rate, myocardial contractility, and aqueous humor production
Indications
Hypertension (oral)Open-angle glaucoma / ocular hypertension (ophthalmic)Migraine prophylaxis (oral)Post-myocardial infarction secondary preventionAtrial fibrillation rate control
Dosing
- Adult
- Hypertension: 10mg PO BID initially, may increase to 20-30mg BID (max 60mg/day). Migraine prophylaxis: 10mg PO BID. Glaucoma: 0.25-0.5% solution/drops 1 drop BID in affected eye(s).
- Pediatric
- Not established for oral use in children. Ophthalmic: safety established in infants for glaucoma.
- Renal adjustment
- No specific adjustment needed; metabolites renally excreted.
- Hepatic adjustment
- Use caution; hepatic metabolism may be impaired.
- Geriatric
- Start at lower end of range (5mg BID); monitor for bradycardia and hypotension.
- Max dose
- 60mg/day oral
Pharmacokinetics
Onset
Ocular: IOP reduction within 30 minutes; Oral: BP reduction within 1-2 hours
Peak effect
Ocular: 1-2 hours; Oral: 1-2 hours (Tmax), antihypertensive peak at 2-4 weeks
Duration
Ocular: 12-24 hours; Oral: 12-24 hours
Half-life
~4 hours (oral); ~4.8 hours in elderly
Bioavailability
~50% (oral, extensive first-pass); ~60-78% (ophthalmic systemic)
Protein binding
<10% (equilibrium dialysis); ~60% (ultrafiltration)
Metabolism
Hepatic via CYP2D6 and other CYP enzymes; extensive first-pass effect
Excretion
Primarily renal as metabolites and unchanged drug (~20% unchanged)
Contraindications
- Severe bradycardia
- Second or third-degree AV block
- Sick sinus syndrome
- Cardiogenic shock
- Severe asthma or COPD
- Hypersensitivity to timolol
Side effects
Common
FatigueBradycardiaHypotensionBronchospasmDizzinessSexual dysfunctionCold extremities
Serious
- Severe bradycardia or heart block
- Bronchospasm / asthma exacerbation
- Heart failure decompensation
- Masking of hypoglycemia in diabetics
- Depression
- Corneal anesthesia (ophthalmic)
Pregnancy & lactation
Pregnancy
Small amounts cross placenta; may cause fetal bradycardia, hypoglycemia. Use only if benefit outweighs risk—prefer cardioselective beta-blockers in pregnancy.
Lactation
Excreted in breast milk in small amounts; plasma levels in nursing infants estimated at 1-2% of maternal level. Generally considered compatible but monitor infant for bradycardia and hypoglycemia.
Drug interactions
Amiloride
Severe
Textbook
Hyperkalaemia more likely.
Source: KDT 7e
Sofosbuvir
Severe
Textbook
Severe bradycardia.
Extreme caution advised if amiodarone is co-administered with sofosbuvir and a beta blocker.
Source: Harrison 22e · unknown
Aminophylline
Severe
Database
Drug interaction classified as: antagonism
Source: DDInter
Arformoterol
Severe
Database
Drug interaction classified as: antagonism
Source: DDInter
Atazanavir
Severe
Database
Drug interaction classified as: synergy
Source: DDInter
Ceritinib
Severe
Database
Drug interaction classified as: synergy
Source: DDInter
Clonidine
Severe
Database
Beta-blocker masks clonidine withdrawal rebound hypertension; abrupt discontinuation of either can cause hypertensive crisis.
Withdraw beta-blocker first, then taper clonidine over several days. Monitor BP closely.
Source: Kimi deep-research + Cla
Diltiazem
Severe
Database
Increased propensity for AV block, severe bradycardia, and decreased left ventricular function.
Avoid concurrent administration. The concurrent administration of diltiazem with a beta blocker is contraindicated.
Source: DDInter
Dolasetron
Severe
Database
Clinical effect not specified
Source: DDInter
Dyphylline
Severe
Database
Clinical effect not specified
Source: DDInter
Formoterol
Severe
Database
Clinical effect not specified
Source: DDInter
Related guidelines
Ask House about Timolol
Continue into a citation-backed clinical answer with the drug context already attached.
Sources: KD Tripathi 7e, Goodman & Gilman 14e, Katzung, BNF·Verified: 2026-05-19 · House clinical team·Cockpit curated: 2026-05-19