Diazepam at high doses has been found to decrease histamine turnover in mouse brain via diazepam's action at the benzodiazepine-GABA receptor complex. Diazepam binds with high affinity to glial cells in animal cell cultures. .  Diazepam also decreases prolactin release in rats.
. The mechanism of tolerance to benzodiazepines includes uncoupling of receptor sites, alterations in gene expression, down-regulation of receptor sites, and desensitisation of receptor sites to the effect of GABA. About one-third of individuals who take benzodiazepines for longer than four weeks become dependent and experience withdrawal syndrome on cessation.   Tolerance develops to the therapeutic effects of benzodiazepines; for example tolerance occurs to the anticonvulsant effects and as a result benzodiazepines are not generally recommended for the long-term management of epilepsy. Dose increases may overcome the effects of tolerance, but tolerance may then develop to the higher dose and adverse effects may increase. Benzodiazepine treatment should be discontinued as soon as possible by a slow and gradual dose reduction regimen.
. The muscle relaxant properties of diazepam are produced via inhibition of polysynaptic pathways in the spinal cord.
Patients from the aforementioned groups should be monitored very closely during therapy for signs of abuse and development of dependence. Therapy should be discontinued if any of these signs are noted, although if dependence has developed, therapy must still be discontinued gradually to avoid severe withdrawal symptoms. Long-term therapy in such instances is not recommended.  .
  Benzodiazepines do not have any pain-relieving properties themselves, and are generally recommended to avoid in individuals with pain. Diazepam is used for the emergency treatment of eclampsia, when IV magnesium sulfate and blood-pressure control measures have failed.   Tolerance often develops to the muscle relaxant effects of benzodiazepines such as diazepam.  However, benzodiazepines such as diazepam can be used for their muscle-relaxant properties to alleviate pain caused by muscle spasms and various dystonias, including blepharospasm.  Baclofen  or tizanidine is sometimes used as an alternative to diazepam.
. Agents with an effect on hepatic cytochrome P450 pathways or conjugation can alter the rate of diazepam metabolism. These interactions would be expected to be most significant with long-term diazepam therapy, and their clinical significance is variable.
 It is commonly used to treat a range of conditions including anxiety, alcohol withdrawal syndrome, benzodiazepine withdrawal syndrome, muscle spasms, seizures, trouble sleeping, and restless legs syndrome.  By mouth, effects may take 40 minutes to begin.   It can be taken by mouth, inserted into the rectum, injected into muscle, or injected into a vein.  When given into a vein, effects begin in one to five minutes and last up to an hour.  It may also be used to cause memory loss during certain medical procedures. . Diazepam, first marketed as Valium, is a medicine of the benzodiazepine family that typically produces a calming effect.
 In humans, tolerance to the anticonvulsant effects of diazepam occurs frequently. Rebound anxiety, more severe than baseline anxiety, is also a common withdrawal symptom when discontinuing diazepam or other benzodiazepines. .  Diazepam is therefore only recommended for short-term therapy at the lowest possible dose owing to risks of severe withdrawal problems from low doses even after gradual reduction.  The risk of pharmacological dependence on diazepam is significant, and patients experience symptoms of benzodiazepine withdrawal syndrome if it is taken for six weeks or longer.
Benzodiazepine drugs including diazepam increase the inhibitory processes in the cerebral cortex. Diazepam appears to act on areas of the limbic system, thalamus, and hypothalamus, inducing anxiolytic effects. .
Because flumazenil is a short-acting drug, and the effects of diazepam can last for days, several doses of flumazenil may be necessary. This drug is only used in cases with severe respiratory depression or cardiovascular complications. Hypotension may be treated with levarterenol or metaraminol. Although not usually fatal when taken alone, a diazepam overdose is considered a medical emergency and generally requires the immediate attention of medical personnel. Emesis is contraindicated. Dialysis is minimally effective. The antidote for an overdose of diazepam (or any other benzodiazepine) is flumazenil (Anexate). Though not routinely indicated, activated charcoal can be used for decontamination of the stomach following a diazepam overdose. Artificial respiration and stabilization of cardiovascular functions may also be necessary.    .
 At a particularly high risk for diazepam misuse, abuse or dependence are:. Improper or excessive use of diazepam can lead to dependence.
Patients with severe attacks of apnea during sleep may suffer respiratory depression (hypoventilation), leading to respiratory arrest and death.
Withdrawal from diazepam or other benzodiazepines often leads to withdrawal symptoms similar to those seen during barbiturate or alcohol withdrawal. The higher the dose and the longer the drug is taken, the greater the risk of experiencing unpleasant withdrawal symptoms. Diazepam, as with other benzodiazepine drugs, can cause tolerance, physical dependence, substance use disorder, and benzodiazepine withdrawal syndrome.
Diazepam does not increase or decrease hepatic enzyme activity, and does not alter the metabolism of other compounds. No evidence would suggest diazepam alters its own metabolism with chronic administration. .
Use of diazepam should be avoided, when possible, in individuals with: 
 It is supplied in oral, injectable, inhalation, and rectal forms. Diazepam is marketed in over 500 brands throughout the world.   .
. It is also used as a premedication for inducing sedation, anxiolysis, or amnesia before certain medical procedures (e.g., endoscopy ). Diazepam is mainly used to treat anxiety, insomnia, panic attacks and symptoms of acute alcohol withdrawal.   Diazepam is the drug of choice for treating benzodiazepine dependence with its long half-life allowing easier dose reduction. Benzodiazepines have a relatively low toxicity in overdose.
Intravenous diazepam or lorazepam are first-line treatments for status epilepticus.   However, intravenous lorazepam has advantages over intravenous diazepam, including a higher rate of terminating seizures and a more prolonged anticonvulsant effect. Diazepam gel was better than placebo gel in reducing the risk of non-cessation of seizures.  .  Diazepam is rarely used for the long-term treatment of epilepsy because tolerance to its anticonvulsant effects usually develops within six to 12 months of treatment, effectively rendering it useless for that purpose.
Diazepam has a number of uses including:
Binding of benzodiazepines to this receptor complex promotes binding of GABA, which in turn increases the total conduction of chloride ions across the neuronal cell membrane. The GABA A receptors are ligand-gated chloride-selective ion channels that are activated by GABA, the major inhibitory neurotransmitter in the brain. As a result, the difference between resting potential and threshold potential is increased and firing is less likely. This increased chloride ion influx hyperpolarizes the neuron's membrane potential. As a result, the arousal of the cortical and limbic systems in the central nervous system is reduced. . Benzodiazepines are positive allosteric modulators of the GABA type A receptors ( GABA A ).
For example, a random sample of long-term benzodiazepine users typically finds around 50% experience few or no withdrawal symptoms, with the other 50% experiencing notable withdrawal symptoms. Differences in rates of withdrawal (50–100%) vary depending on the patient sample. . Certain select patient groups show a higher rate of notable withdrawal symptoms, up to 100%.
 Very rarely dystonia can occur. . These adverse reactions are more likely to occur in children, the elderly, and individuals with a history of drug or alcohol abuse and or aggression. Less commonly, paradoxical side effects can occur, including nervousness, irritability, excitement, worsening of seizures, insomnia, muscle cramps, changes in libido, and in some cases, rage and violence.     Diazepam may increase, in some people, the propensity toward self-harming behaviours and, in extreme cases, may provoke suicidal tendencies or acts.
Equal prudence should be used whether dependence has occurred in therapeutic or recreational contexts. People suspected of being dependent on benzodiazepine drugs should be very gradually tapered off the drug. Withdrawals can be life-threatening, particularly when excessive doses have been taken for extended periods of time.
The GABA A receptor is a heteromer composed of five subunits, the most common ones being two αs, two βs, and one γ (α2β2γ). GABA A receptors containing the α1 subunit mediate the sedative, the anterograde amnesic, and partly the anticonvulsive effects of diazepam. .  Diazepam is not the only drug to target these GABA A receptors. For each subunit, many subtypes exist (α1–6, β1–3, and γ1–3). GABA A receptors containing α2 mediate the anxiolytic actions and to a large degree the myorelaxant effects. Drugs such as flumazenil also bind to GABA A to induce their effects. GABA A receptors containing α3 and α5 also contribute to benzodiazepines myorelaxant actions, whereas GABA A receptors comprising the α5 subunit were shown to modulate the temporal and spatial memory effects of benzodiazepines.
. During the course of therapy, tolerance to the sedative effects usually develops, but not to the anxiolytic and myorelaxant effects.
 Infusions or repeated intravenous injections of diazepam when managing seizures, for example, may lead to drug toxicity, including respiratory depression, sedation and hypotension. . While benzodiazepine drugs such as diazepam can cause anterograde amnesia, they do not cause retrograde amnesia ; information learned before using benzodiazepines is not impaired. Tolerance to the cognitive-impairing effects of benzodiazepines does not tend to develop with long-term use, and the elderly are more sensitive to them. Long-term use of benzodiazepines such as diazepam is associated with drug tolerance, benzodiazepine dependence, and benzodiazepine withdrawal syndrome.  Sedatives and sleeping pills, including diazepam, have been associated with an increased risk of death. Drug tolerance may also develop to infusions of diazepam if it is given for longer than 24 hours.  Additionally, after cessation of benzodiazepines, cognitive deficits may persist for at least six months; it is unclear whether these impairments take longer than six months to abate or if they are permanent.  Adverse effects such as sedation, benzodiazepine dependence, and abuse potential limit the use of benzodiazepines.  Like other benzodiazepines, diazepam can impair short-term memory and learning of new information. Adverse effects of benzodiazepines such as diazepam include anterograde amnesia and confusion (especially pronounced in higher doses) and sedation. The elderly are more prone to adverse effects of diazepam, such as confusion, amnesia, ataxia, and hangover effects, as well as falls. Benzodiazepines may also cause or worsen depression.
 Recurrence rates are reduced, but side effects are common. .  Long-term use of diazepam for the management of epilepsy is not recommended; however, a subgroup of individuals with treatment-resistant epilepsy benefit from long-term benzodiazepines, and for such individuals, clorazepate has been recommended due to its slower onset of tolerance to the anticonvulsant effects. Diazepam is sometimes used intermittently for the prevention of febrile seizures that may occur in children under five years of age.
Dosages should be determined on an individual basis, depending on the condition being treated, severity of symptoms, patient body weight, and any other conditions the person may have. .
Greenblatt and colleagues reported in 1978 on two patients who had taken 500 and 2000 mg of diazepam, respectively, went into moderay deep comas, and were discharged within 48 hours without having experienced any important complications, in spite of having high concentrations of diazepam and its metabolites desmethyldiazepam, oxazepam, and temazepam, according to samples taken in the hospital and as follow-up. . The oral LD 50 (lethal dose in 50% of the population) of diazepam is 720 mg/kg in mice and 1240 mg/kg in rats. J.  D.
Diazepam may impair the ability to drive vehicles or operate machinery. The impairment is worsened by consumption of alcohol, because both act as central nervous system depressants. .
The United States military employs a specialized diazepam preparation known as Convulsive Antidote, Nerve Agent (CANA), which contains diazepam. Both of these kits deliver drugs using autoinjectors. . One CANA kit is typically issued to service members, along with three Mark I NAAK kits, when operating in circumstances where chemical weapons in the form of nerve agents are considered a potential hazard. They are intended for use in "buddy aid" or "self aid" administration of the drugs in the field prior to decontamination and delivery of the patient to definitive medical care.
This has been found by measuring sodium-dependent high-affinity choline uptake in mouse brain cells in vitro, after pretreatment of the mice with diazepam in vivo. Diazepam inhibits acetylcholine release in mouse hippocampal synaptosomes. . This may play a role in explaining diazepam's anticonvulsant properties.
. Diazepam can be administered orally, intravenously (must be diluted, as it is painful and damaging to veins), intramuscularly (IM), or as a suppository.
 Peak plasma levels occur between 30 and 90 minutes after oral administration and between 30 and 60 minutes after intramuscular administration; after rectal administration, peak plasma levels occur after 10 to 45 minutes. The duration of diazepam's peak pharmacological effects is 15 minutes to one hour for both routes of administration. When administered orally, it is rapidly absorbed and has a fast onset of action.  The bioavailability after oral administration is 100%, and 90% after rectal administration. The onset of action is one to five minutes for IV administration and 15–30 minutes for IM administration. The half-life of diazepam in general is 30–56 hours. The distribution half-life of diazepam is two to 13 minutes. . Diazepam is highly protein-bound, with 96 to 99% of the absorbed drug being protein-bound.
An individual who has consumed too much diazepam typically displays one or more of these symptoms in a period of approximay four hours immediay following a suspected overdose:  
 . Overdoses of diazepam with alcohol, opiates or other depressants may be fatal.
Particular care should be taken with drugs that potentiate the effects of diazepam, such as barbiturates, phenothiazines, opioids, and antidepressants. . If diazepam is administered concomitantly with other drugs, attention should be paid to the possible pharmacological interactions.
 Diazepam has no effect on GABA levels and no effect on glutamate decarboxylase activity, but has a slight effect on gamma-aminobutyric acid transaminase activity. Diazepam is a long-acting "classical" benzodiazepine.  Diazepam has anticonvulsant properties.  It differs from some other anticonvulsive drugs with which it was compared.  Benzodiazepines act via micromolar benzodiazepine binding sites as calcium channel blockers and significantly inhibit depolarization-sensitive calcium uptake in rat nerve cell preparations. . Other classical benzodiazepines include chlordiazepoxide, clonazepam, lorazepam, oxazepam, nitrazepam, temazepam, flurazepam, bromazepam, and clorazepate.
Withdrawal symptoms can occur from standard dosages and also after short-term use, and can range from insomnia and anxiety to more serious symptoms, including seizures and psychosis. Withdrawal symptoms can sometimes resemble pre-existing conditions and be misdiagnosed. Diazepam may produce less intense withdrawal symptoms due to its long elimination half-life.
The anticonvulsant effects of diazepam can help in the treatment of seizures due to a drug overdose or chemical toxicity as a result of exposure to sarin, VX, or soman (or other organophosphate poisons), lindane, chloroquine, physostigmine, or pyrethroids.  .
. Diazepam in doses of 5 mg or more causes significant deterioration in alertness performance combined with increased feelings of sleepiness.
Diazepam has a range of side effects common to most benzodiazepines, including:
Sustained repetitive firing seems limited by benzodiazepines' effect of slowing recovery of sodium channels from inactivation. . The anticonvulsant properties of diazepam and other benzodiazepines may be in part or entirely due to binding to voltage-dependent sodium channels rather than benzodiazepine receptors.
 Its mechanism of action is by increasing the effect of the neurotransmitter gamma -aminobutyric acid (GABA). .  It is not recommended during pregnancy or breastfeeding.  Abrupt stopping after long-term use can be potentially dangerous.  They include suicide, decreased breathing, and an increased risk of seizures if used too frequently in those with epilepsy.    Occasionally excitement or agitation may occur.  Serious side effects are rare. Common side effects include sleepiness and trouble with coordination.  After stopping, cognitive problems may persist for six months or longer.   Long term use can result in tolerance, dependence, and withdrawal symptoms on dose reduction.
.  In the United States, it is about 0.40 USD per dose.  It has been one of the most frequently prescribed medications in the world since its launch in 1963.  In the United States it was the highest selling medication between 1968 and 1982, selling more than two billion tablets in 1978 alone.  Diazepam is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system. Diazepam was first made by Leo Sternbach and commercialized by Hoffmann-La Roche.  The wholesale cost in the developing world is about 0.01 USD per dose as of 2014.  In 1985 the patent ended, and there are now more than 500 brands available on the market.Valium