Brand Name: Valium, Diastat

Available in 2 mg, 5 mg and 10 mg tablets, injectable, oral solution

Uses of this Medication

There are many uses for this medication since it is effective as an anti-anxiety medication, a muscle relaxant, an appetite stimulant, and a seizure control drug. The injectable form of diazepam is often used with anesthesia.

Examples of more specific uses for diazepam include:

• Treatment of seizure disorders (as an injectable, anal suppository, or even nasally during an emergency)
• Treatment of "Scotty cramp" and other muscle-cramping diseases
• Treatment of irritable bowel syndrome
• Panic disorders, such as thunderstorm or fireworks phobias in dogs
• As a muscle relaxant in snail bait poisoning or in other situations of extreme involuntary muscle contraction.

In the past, diazepam was regarded to have many feline uses, from the treatment of territorial anxiety/inappropriate urination to seizure disorders. Some cats have a unique and unpredictable reaction that can become lethal in that liver failure occurs within 5-11 days of starting oral diazepam. Because of this unpredictable reaction and the advent of newer medications, oral use of diazepam in cats is no longer recommended.

How this Medication Works

Diazepam is a psychoactive drug of the benzodiazepine class. It works by altering the receptor for an inhibitory neurotransmitter called GABA. The result is enhanced GABA binding to the receptor with resulting sedation, muscle relaxation, and resolution of anxiety. 

The oral form of this medication is primarily used in dogs, though injectable forms can be used as nasal or rectal liquids for emergency seizure control at home. The oral form has been problematic for cats, as mentioned because some individual cats develop a serious liver reaction within 5-11 days of beginning treatment. Because of this reaction, usually, other oral medication choices are selected for feline patients. Injectable forms do not seem to have this issue. 

Oral diazepam can be given with or without food, and if a dose is accidentally skipped, the next dose should be given as planned without doubling up. As for injectable solutions used nasally or rectally, your veterinarian should provide you with instructions about re-dosing should seizures continue after one administration.

Side Effects

As with many medications, it is difficult to sort out the side effects from the desired effects since there are many uses for this drug. Diazepam is rarely used as a tranquilizer for animals as it simply is not very long-lasting and not very reliable; furthermore, undesired sedating effects are reported when this medication is used.  Some animals paradoxically get hyper-excited on diazepam.

Diazepam is sometimes used as an appetite stimulant, but its sedating properties preclude it from being the drug of choice for this purpose. See anorexia for better options.

In the cat, the unpredictable liver disease side effect has rendered this medication a poor choice for oral use.

Interactions with Other Drugs

Diazepam may have a stronger than expected effect if used in conjunction with cimetidine (an antacid more commonly known as Tagamet®), omeprazole (an antacid more commonly known as Prilosec®), erythromycin (an antibiotic), ketoconazole or other "azole" antifungal drugs, fluoxetine (an anti-anxiety medication), or propranolol (a heart medication).

Antacids may slow the onset of diazepam's effect.

The use of diazepam may increase the effect of digoxin, a heart medication, and of amitriptyline, an anti-anxiety medication.

Concerns and Cautions

This medication should be stored at room temperature and protected from light.

Urine dipsticks that measure glucose may be falsely negative in patients taking diazepam.

Discontinuing diazepam abruptly may lead to unpleasant withdrawal symptoms similar to those that occur in humans.

Diazepam should not be used in early pregnancy, as birth defects have been reported.

Diazepam also crosses readily into the milk of nursing mothers and may tranquilize nursing young, so it should not be used in nursing mothers.