Amitriptyline
Severe
Textbook-cited
Exaggerated hypertensive response
Use local anaesthetic without adrenaline in patients on TCAs
Source: KDT 7e · p950
Drug reference
Epinephrine
Endogenous catecholamine (alpha + beta adrenergic agonist) · Bronchodilator
Also known as Adrenaline, Epinephrine Bitartrate, Epinephrine Hydrochloride
START
Anaphylaxis 0.3–0.5 mg IM (1:1000) thigh, repeat q5–15 min; arrest 1 mg IV (1:10,000) q3–5 min
TYPICAL MAX
Anaphylaxis ~0.5 mg/IM dose (repeat PRN); arrest 1 mg IV q3–5 min — do not delay in emergency
STOP IF
In emergencies do not withhold; for non-emergency infusion stop if severe arrhythmia/ischaemia/hypertension
WATCH
Route/concentration accuracy (1:1000 IM vs 1:10,000 IV), ECG/BP, response, biphasic anaphylaxis observation
CDSCO approvedSchedule HATC C01CA24
KDIGO 2024 + manufacturer label
- ONSET
- 5min · IM onset (~5 min)
- PEAK
- 10min · IM peak (~10 min)
- t½
- 2min · plasma t½ (~2.5 min)
- DURATION
- 8min · IM effect (~8 min)
EXCRETION
COMT/MAO metabolism; renal metabolites
route + CYP
INTERACTIONS
12 major
SEVERE in our sources
PREGNANCY
Use without hesitation in anaphylaxis/arrest — benefit outweighs risk (untreated anaphylaxis is more dangerous)
FDA category + note
Top interactionssee all 12 →
- AmitriptylineSevereTextbook-citedKDT 7e · p950
- ClomipramineSevereTextbook-citedKDT 7e · p950
- ImipramineSevereTextbook-citedKDT 7e · p950
- NortriptylineSevereTextbook-citedKDT 7e · p950
Available in India
8 branded formulations and 15 fixed-dose combinations. Look up specific brands in the Drugs workspace.
Mechanism
Non-selective adrenergic agonist: alpha-1 vasoconstriction (raises BP, reduces mucosal/airway oedema), beta-1 inotropy/chronotropy, beta-2 bronchodilation and mast-cell stabilisation — the definitive treatment of anaphylaxis and a cardiac-arrest vasopressor.
Indications
Anaphylaxis (first-line)Cardiac arrest (ACLS)Severe symptomatic bradycardia/hypotension (infusion)Adjunct in local anaesthesia (vasoconstrictor); croup/severe bronchospasm (nebulised)
Dosing
- Adult
- Anaphylaxis: 0.3–0.5 mg IM (1:1000) anterolateral thigh, repeat every 5–15 min PRN. Cardiac arrest: 1 mg IV/IO (1:10,000) every 3–5 min. Refractory anaphylaxis/hypotension: IV infusion 0.05–0.1 mcg/kg/min titrated.
- Pediatric
- Anaphylaxis 0.01 mg/kg IM (max 0.3–0.5 mg); arrest 0.01 mg/kg IV/IO.
- Renal adjustment
- No adjustment (emergency).
- Hepatic adjustment
- No adjustment.
- Geriatric
- Standard emergency doses; cautious IV use (ischaemia/arrhythmia).
- Max dose
- Anaphylaxis IM ~0.5 mg/dose (repeat PRN); arrest 1 mg IV q3–5 min
Pharmacokinetics
Onset
IM 5–10 min; IV seconds
Peak effect
IM ~10 min; IV ~1 min
Duration
~5–10 min (IM); shorter IV
Half-life
~2–3 min
Bioavailability
IM/IV (not oral)
Protein binding
~50%
Metabolism
COMT/MAO (rapid)
Excretion
Renal (metabolites — metanephrine/VMA)
Contraindications
- No absolute contraindication in life-threatening anaphylaxis/arrest
- Caution (non-emergency use): severe coronary disease, tachyarrhythmia, phaeochromocytoma, uncorrected hyperthyroidism
- Do not use local-anaesthetic-with-adrenaline in end-arterial fields (digits, etc. — traditional caution)
Side effects
Common
Palpitations/tachycardiaTremor, anxietyHeadachePallor, sweatingTransient hypertension
Serious
- Myocardial ischaemia/infarction, arrhythmia (esp. IV/overdose)
- Severe hypertension → intracranial haemorrhage
- Pulmonary oedema
- Tissue ischaemia/necrosis (extravasation, accidental digital injection)
Pregnancy & lactation
Pregnancy
Use without hesitation in anaphylaxis/arrest — benefit outweighs risk (untreated anaphylaxis is more dangerous)
Lactation
Compatible — not orally bioavailable, very short t½
Drug interactions
Clomipramine
Severe
Textbook-cited
Exaggerated hypertensive response
Use local anaesthetic without adrenaline in patients on TCAs
Source: KDT 7e · p950
Imipramine
Severe
Textbook-cited
Exaggerated hypertensive response
Use local anaesthetic without adrenaline in patients on TCAs
Source: KDT 7e · p950
Nortriptyline
Severe
Textbook-cited
Exaggerated hypertensive response.
Use local anaesthetic without adrenaline in patients on TCAs
Source: KDT 7e · p950
Bucindolol
Severe
Textbook
Severe hypertension and cerebral hemorrhage.
The use of epinephrine generally is contraindicated in patients who are receiving nonselective β receptor antagonists.
Source: G&G 14e · p258
Celiprolol
Severe
Textbook
Severe hypertension and cerebral hemorrhage.
The use of epinephrine generally is contraindicated in patients who are receiving nonselective β receptor antagonists.
Source: G&G 14e · p258
Esmolol Hydrochloride
Severe
Textbook
Severe hypertension and cerebral hemorrhage.
The use of epinephrine generally is contraindicated in patients who are receiving nonselective β receptor antagonists.
Source: G&G 14e · p258
Amitriptyline
Severe
Database
Increased effect of epinephrine, potentially leading to cardiovascular complications.
Precautions should be taken. Use minimal amount of vasoconstrictor necessary for good hemostasis and local anesthesia.
Source: DDInter
Amoxapine
Severe
Database
Increased effect of epinephrine, potentially leading to cardiovascular complications.
Precautions should be taken. Use minimal amount of vasoconstrictor necessary for good hemostasis and local anesthesia.
Source: DDInter
Carteolol
Severe
Database
Severe hypertension and cerebral hemorrhage.
The use of epinephrine generally is contraindicated in patients who are receiving nonselective β receptor antagonists.
Source: DDInter
Carvedilol
Severe
Database
Severe hypertension and cerebral hemorrhage.
The use of epinephrine generally is contraindicated in patients who are receiving nonselective β receptor antagonists.
Source: DDInter
Chlorpromazine
Severe
Database
Paradoxical hypotension and tachycardia, potentially leading to cardiovascular collapse.
Avoid using epinephrine to treat hypotension in patients on chlorpromazine. If a vasopressor is needed, use norepinephrine or phenylephrine.
Source: DDInter
Related guidelines
Ask House about Epinephrine
Continue into a citation-backed clinical answer with the drug context already attached.
Sources: Goodman & Gilman 14e, Katzung, BNF, Nelson·Verified: 2026-05-19 · House clinical team·Cockpit curated: 2026-05-19