Diazepam
7-chloro-1-methyl-5-phenyl-1,3-dihydro-2H-1,4-benzodiazepin-2-one
Also known as: Valium · Diastat · Diazepam Intensol · Diazedor · Diazemuls · Stesolid · Diazepam Rectubes · diazepamum · LA-III · NSC-77518 · Ro5-2807
Reviewed by the VetSheet Veterinary TeamUpdated Apr 5, 2026Evidence-based veterinary reference
Audited v13 dosing evidence
Reviewed non-calculator evidenceReviewed non-calculator evidence (1)
Evidence only — not for automatic calculation
Persistent seizures during an insulinoma hypoglycemic crisis despite IV dextrose
Diazepam if seizures persist despite IV dextrose
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Overview
Diazepam is a classic, long-acting benzodiazepine derivative widely utilized in veterinary medicine for its anxiolytic, muscle relaxant, hypnotic, appetite-stimulating, and anticonvulsant properties.
Clinical Pearls:
- Seizure Management: Diazepam is a first-line drug of choice for the emergency treatment of status epilepticus and cluster seizures. However, it is generally ineffective as a long-term maintenance anticonvulsant in dogs due to its short duration of action and the rapid development of tolerance.
- Feline Considerations: While tolerance is less of an issue in cats, oral administration of diazepam is highly controversial due to the risk of idiosyncratic, potentially fatal fulminant hepatic necrosis.
- Formulation Quirk: The injectable formulation contains propylene glycol, which can cause hypotension, bradycardia, and cardiotoxicity if administered too rapidly intravenously. It also readily adsorbs to PVC plastics, making it unsuitable for storage in plastic syringes or prolonged administration via standard IV fluid bags.
Mechanism of action
Diazepam exerts its effects by binding to specific allosteric sites on GABA-A receptors in the central nervous system (primarily in the limbic system, thalamus, and hypothalamus).
- Binding to the benzodiazepine site → enhances the affinity of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA) for its receptor.
- This facilitation → increases the frequency of chloride channel opening → influx of chloride ions → neuronal hyperpolarization.
- The resulting hyperpolarization leads to profound CNS depression, producing anxiolytic, sedative, muscle relaxant, and anticonvulsant effects.
Safety & warnings
Contraindications
- Known hypersensitivity to benzodiazepines
- Cats exposed to chlorpyrifos (potentiates organophosphate toxicity)
- Significant liver disease (especially in cats)
- Intra-carotid artery injections (must be strictly avoided)
- CNS depression
- Respiratory depression
- Severe muscle weakness
- Hepatic impairment (may worsen hepatic encephalopathy)
- Long-term treatment of behavioural disorders (due to risks of disinhibition and interference with memory/learning)
Adverse effects
- Sedation and ataxia (most common)
- Dogs: Paradoxical CNS excitement/agitation (especially at doses >0.8 mg/kg)
- Dogs: Increased appetite
- Cats: Idiosyncratic hepatic failure (with oral use)
- Cats: Behavior changes (irritability, depression, aberrant demeanor)
- Horses: Muscle fasciculations, weakness, ataxia, recumbency (at doses >0.2 mg/kg)
- Hypotension and phlebitis (with rapid IV injection)
- Muscle weakness
- Paradoxical excitation and aggression (especially with rapid IV injection or oral overdose in dogs)
- Pain and erratic absorption (IM injection)
- Fulminant hepatic necrosis (cats, repeated oral dosing)
- Thrombophlebitis (associated with propylene glycol injectable formulations)
Precautions
Intravenous Administration: Inject IV slowly (over 1-3 minutes). Rapid injection, especially in small animals or neonates, may cause hypotension or cardiotoxicity secondary to the propylene glycol vehicle. Flush the IV catheter with fluids after administration to help prevent thrombophlebitis.
Feline Hepatotoxicity: Use in cats is controversial due to reports of serious, potentially fatal idiosyncratic hepatotoxicity associated with oral administration. Baseline and follow-up liver function tests are strongly recommended if used.
- Patient Selection: Use cautiously in patients with hepatic or renal disease, debilitated or geriatric patients, and those in coma, shock, or with significant respiratory depression.
- Behavioral Disinhibition: Use very cautiously in aggressive patients, as it may disinhibit anxiety that normally suppresses aggressive behavior.
- Working Animals: May impair the abilities of working animals.
- Toxicity Treatment: Do not use to treat paradoxical CNS stimulation caused by human sleep aids (zolpidem, eszopiclone); use phenothiazines or phenobarbital instead.
- Pregnancy: May be teratogenic (FDA Category D). Use during the first trimester only if benefits clearly outweigh risks.
Drug interactions
May increase diazepam levels
May decrease oral diazepam absorption
May increase diazepam levels by inhibiting metabolism
May decrease metabolism of benzodiazepines
Additive CNS depression effects may occur
May decrease diazepam levels
Diazepam may increase digoxin levels
May decrease the metabolism of benzodiazepines
May decrease oral diazepam absorption
May inhibit the metabolism of diazepam and increase levels
May decrease diazepam concentrations
May decrease diazepam concentrations
May increase diazepam levels
May induce hepatic microsomal enzymes and decrease the pharmacologic effects of benzodiazepines
Enhanced sedative effect
Enhanced sedative effect
Diazepam reduces the dose requirement of other anaesthetic agents
Can be used in combination for management of severe behavioural responses
Reverses the effects of diazepam (benzodiazepine antagonist)
Monitoring
- Horses should be observed carefully after receiving this drug.
- Cats receiving oral diazepam must have baseline liver function tests. Repeat and discontinue drug if emesis, lethargy, inappetence, or ataxia develop.
- When used for seizure control in cats, obtain serum levels 5 days after beginning therapy (therapeutic goal: 200-700 ng/mL or 2500-700 nmol/L).
- Hepatic function (especially in cats)
- Respiratory rate and effort
- Level of CNS depression / sedation
- Seizure activity
Pharmacokinetics
Half-life
Absorption
Rapidly absorbed following oral administration (peak plasma levels within 30 mins to 2 hours). Slowly and incompletely absorbed following IM administration. Rectal bioavailability in dogs is <10% for parent drug, but ~80% when factoring in active metabolites. Intranasal bioavailability in dogs is ~80%.
Distribution
Highly lipid soluble and widely distributed throughout the body. Readily crosses the blood-brain barrier. Highly bound to plasma proteins (87% in horses, 98-99% in humans).
Metabolism
Metabolized in the liver to several pharmacologically active metabolites, including desmethyldiazepam (nordiazepam), temazepam, and oxazepam.
Elimination
Metabolites are conjugated with glucuronide and eliminated primarily in the urine.
Overdose
When administered alone, diazepam overdoses are generally limited to significant CNS depression (confusion, coma, decreased reflexes, etc.). Hypotension, respiratory depression, and cardiac arrest have been reported in human patients, but are quite rare.
Treatment:
- Standard protocols for removing and/or binding the drug in the gut if taken orally (e.g., emesis, activated charcoal).
- Supportive systemic measures (fluids, respiratory support if needed).
- The use of analeptic agents (CNS stimulants like caffeine) is generally not recommended.
- Flumazenil (a specific benzodiazepine antagonist) may be considered for adjunctive treatment of severe overdoses.
Available products
Formulations
- Oral tablets
- Oral solution
- Injectable solution
- Rectal gel
- Injectable: 5 mg/ml emulsion (e.g., Diazemuls)
- Oral: 2 mg, 5 mg, 10 mg tablets
- Oral: 2 mg/5 ml solution
- Rectal: 2 mg/ml and 4 mg/ml solutions
- Rectal: 10 mg suppositories
Veterinary
- None (No veterinary-labeled products available)
- Diazedor
- Diazemuls
- Diazepam Rectubes
Human-labeled
- Diazepam Oral Tablets: 2 mg, 5 mg, & 10 mg (Valium, generic)
- Diazepam Oral Solution: 1 mg/mL and 5 mg/mL (Diazepam Intensol)
- Diazepam Injection: 5 mg/mL
- Diazepam Rectal Gel: 2.5 mg, 10 mg, & 20 mg (Diastat)
- Stesolid
Regulatory status
POM-V, POM
POM-V, POM
No regulatory data for: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Storage & stability
Store all products at room temperature (15°-30°C). Protect injection from freezing and light. Protect oral forms from light. Important: Diazepam adsorbs to plastic; do not store drawn up in plastic syringes or administer through PVC IV bags/tubing for prolonged periods.
Client information
- Storage: Keep out of reach of children and other pets. Store in tightly closed containers. This is a controlled substance.
- Administration: Give exactly as prescribed. If using rectally for seizures at home, follow your veterinarian's instructions carefully on how to administer the dose safely.
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CRITICAL WARNING FOR CATS: If your cat is taking this medication and develops a lack of appetite, vomits, or shows yellowish whites of the eyes or gums (jaundice), stop the medication and contact your veterinarian immediately, as this can be a sign of severe liver damage.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.