Thiopental
Contraindicated
Textbook
Chemical reaction occurs when mixed.
Should not be mixed in the same syringe.
Source: KDT 7e · p347-359
Drug reference
Succinylcholine
Depolarising neuromuscular blocker (ultra-short) · Skeletal Muscle Relaxant; Adjunct to Anesthesia
Also known as Suxamethonium, Suxamethonium Chloride, Anectine, Quelicin
START
RSI: 1–1.5 mg/kg IV (≈100 mg adult)
TYPICAL MAX
150 mg single IM; IV titrated to effect
STOP IF
Suspected MH, hyperkalaemia, or prolonged apnoea
WATCH
ECG/K+, temperature/ETCO2 (MH), neuromuscular recovery
CDSCO approvedSchedule HATC M03AB01
KDIGO 2024 + manufacturer label
- ONSET
- 36s · 30–60 s
- PEAK
- 1min · full block
- t½
- 43s · t½ ~0.7 min
- DURATION
- 6min · 4–6 min
EXCRETION
Plasma pseudocholinesterase hydrolysis; ~10% renal
route + CYP
INTERACTIONS
12 major
incl. contraindicated
PREGNANCY
Acceptable for obstetric anaesthesia (minimal placental transfer).
FDA category + note
Top interactionssee all 12 →
- ThiopentalContraindicatedTextbookKDT 7e · p347-359
- Volatile AnaestheticsContraindicatedDatabaseKimi deep-research + Cla
- LithiumSevereTextbookKDT 7e
- AmikacinSevereDatabaseDDInter
Available in India
6 branded formulations. Look up specific brands in the Drugs workspace.
Mechanism
Binds nicotinic ACh receptors at the motor end-plate causing persistent depolarisation (phase I block) → transient fasciculations then flaccid paralysis; hydrolysed by plasma pseudocholinesterase.
Indications
Rapid-sequence intubation (muscle relaxation)Short procedures requiring brief paralysisModified electroconvulsive therapy
Dosing
- Adult
- RSI: 1–1.5 mg/kg IV. IM (no IV access): 3–4 mg/kg (max 150 mg). Infusion (rare): 2.5–4.3 mg/min.
- Pediatric
- IV 1–2 mg/kg (infants 2–3 mg/kg); IM up to 4 mg/kg; pretreat atropine for bradycardia.
- Renal adjustment
- No adjustment for single dose; caution with hyperkalaemia in renal failure.
- Hepatic adjustment
- Severe hepatic disease may lower pseudocholinesterase → prolonged block.
- Geriatric
- Usual weight-based dosing; monitor recovery.
- Max dose
- 150 mg (single IM dose); titrate IV to effect
Pharmacokinetics
Onset
30–60 s IV (2–3 min IM)
Peak effect
~1 min (complete block)
Duration
4–6 min IV (longer IM)
Half-life
~0.7 min (plasma; pseudocholinesterase hydrolysis)
Bioavailability
IV/IM (not oral)
Protein binding
Minimal
Metabolism
Plasma pseudocholinesterase hydrolysis
Excretion
Renal (~10% unchanged); mostly hydrolysed
Contraindications
- Personal/family history of malignant hyperthermia
- Hyperkalaemia or conditions predisposing to it (major burns, crush, denervation, prolonged immobility)
- Skeletal muscle myopathies
- Acute phase of major burns/trauma (after ~48–72 h)
- Known pseudocholinesterase deficiency
Side effects
Common
Muscle fasciculationsPostoperative myalgiaTransient hyperkalaemiaBradycardia (esp. children/repeat doses)Increased intraocular/intragastric pressure
Serious
- Malignant hyperthermia
- Life-threatening hyperkalaemia/cardiac arrest
- Prolonged apnoea (pseudocholinesterase deficiency)
- Anaphylaxis
- Severe bradycardia/asystole
Pregnancy & lactation
Pregnancy
Acceptable for obstetric anaesthesia (minimal placental transfer).
Lactation
Not relevant (single peri-procedural use; rapidly hydrolysed).
Drug interactions
Volatile Anaesthetics
Contraindicated
Database
MH-trigger synergy
Avoid in MH-susceptible; have dantrolene available
Source: Kimi deep-research + Cla
Lithium
Severe
Textbook
Prolonged paralysis.
Not explicitly stated
Source: KDT 7e
Amikacin
Severe
Database
Clinical effect not specified
Source: DDInter
Botulinum Toxin Type A
Severe
Database
Clinical effect not specified
Source: DDInter
Botulinum Toxin Type B
Severe
Database
Clinical effect not specified
Source: DDInter
Colistimethate
Severe
Database
Clinical effect not specified
Source: DDInter
Gentamicin
Severe
Database
Clinical effect not specified
Source: DDInter
Kanamycin
Severe
Database
Clinical effect not specified
Source: DDInter
Neostigmine
Severe
Database
Neostigmine is not effective against the skeletal muscle paralysis caused by succinylcholine; instead, it will enhance depolarization and the resultant blockade, potentially worsening paralysis.
Avoid combination or use with extreme caution. Neostigmine should not be used to reverse succinylcholine-induced paralysis.
Source: DDInter
Netilmicin
Severe
Database
Clinical effect not specified
Source: DDInter
Paromomycin
Severe
Database
Clinical effect not specified
Source: DDInter
Related guidelines
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MOHFW · Cardiology · 2024
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ADA_DENTAL · Dentistry · 2015
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NICE · Cardiology / Dentistry · 2008
Infective endocarditis prevention
AHA · Cardiology / Dentistry · 2007
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AUA · Urology · 2018
Ask House about Succinylcholine
Continue into a citation-backed clinical answer with the drug context already attached.
Sources: KD Tripathi 7e, Goodman & Gilman 14e, Katzung, BNF·Verified: 2026-05-20 · House clinical team·Cockpit curated: 2026-05-20