Pirahenz

Pirahenz Uses, Dosage, Side Effects, Food Interaction and all others data.

Pirahenz's mechanism of action is not fully understood. The drug influences neuronal and vascular functions and influences cognitive function without acting as a sedative or stimulant. Pirahenz is a positive allosteric modulator of the AMPA receptor. It is hypothesized to act on ion channels or ion carriers, thus leading to increased neuron excitability. GABA brain metabolism and GABA receptors are not affected by piracetam

It has been found to increase blood flow and oxygen consumption in parts of the brain, but this may be a side effect of increased brain activity rather than a primary effect or mechanism of action for the drug.

Pirahenz improves the function of the neurotransmitter acetylcholine via muscarinic cholinergic (ACh) receptors, which are implicated in memory processes. Furthermore, piracetam may have an effect on NMDA glutamate receptors, which are involved with learning and memory processes. Pirahenz is thought to increase cell membrane permeability. Pirahenz may exert its global effect on brain neurotransmission via modulation of ion channels (i.e., Na+, K+). It has been found to increase oxygen consumption in the brain, apparently in connection to ATP metabolism, and increases the activity of adenylate kinase in rat brains. Pirahenz, while in the brain, appears to increase the synthesis of cytochrome b5, which is a part of the electron transport mechanism in mitochondria. But in the brain, it also increases the permeability of the mitochondria of some intermediaries of the Krebs cycle.

Pirahenz is known to mediate various pharmacodynamic actions:

Neuronal effects:

Pirahenz modulates the cholinergic, serotonergic, noradrenergic, and glutamatergic neurotransmission although the drug does not display high affinity to any of the associated receptors (Ki >10μM). Instead, piracetam increases the density of postsynaptic receptors and/or restore the function of these receptors through stabilizing the membrane fluidity . In the forebrain of aging mice, the density of NMDA receptors was increased by approximately 20% following 14 days of piracetam treatment. Based on the findings of various animal and human studies, the cognitive processses including learning, memory, attention and consciousness were enhanced from piracetam therapy without inducing sedation and psychostimulant effects . Pirahenz mediate neuroprotective effects against hypoxia-induced damage, intoxication, and electroconvulsive therapy .

Trade Name Pirahenz
Generic Piracetam
Piracetam Other Names Piracetam, Piracetamum
Type Injection, Tablet
Formula C6H10N2O2
Weight Average: 142.1558
Monoisotopic: 142.074227574
Protein binding

Piracetam is not reported to be bound to plasma proteins .

Groups Approved, Investigational
Therapeutic Class Adjunct anti-epileptic drugs, Drugs used in tremor, tics & related disorder
Manufacturer La Renon Healthcare Pvt Ltd
Available Country India
Last Updated: September 19, 2023 at 7:00 am
Pirahenz
Pirahenz

Uses

Cerebral vascular accidents and cerebral insufficiencies: Ischaemic or even haemorrhagic acute accidents, chronic manifestations of the above accidents or of cerebral atherosclerosis.

Mental retardation in children: Ease of resuming individual contact, sociability and learning, improved intellectual performances and school results.

Behaviour and psychotic problems in old age: Memory deficits, particularly with regard to fixation and evocation asthenia adaption disorders, disturbed psychomotor reactions. Patients suffering from myoclonus of cortical origin.

Pirahenz is also used to associated treatment for these conditions: Alcohol Dependency, Alcohol Withdrawl, Cognitive Deficits caused by Injuries, Craniocerebral, Cognitive Dysfunctions, Cognitive Impairments, Comatose caused by Blood Vessel (Vascular) Dysfunction, Comatose caused by CNS Toxicity, Comatose caused by Traumas, Learning Disorders, Myoclonus, Sickle Cell Disease (SCD), Giddiness caused by Injuries, Craniocerebral

How Pirahenz works

Pirahenz interacts with the polar heads in the phospholipids membrane and the resulting mobile drug-lipid complexes are thought to reorganize the lipids and influence membrane function and fluidity . Such interaction has been reported in a study that investigated the effects of neuronal outgrowth induced by beta amyloid peptides; while amyloid peptides cause lipid disorganization within the cell membranes leading to neuronal death, piracetam demonstrated to decrease the destabilizing effects of amyloid peptide . The authors suggest that piracetam induces a positive curvature of the membrane by occupying the polar groups in the phospholipids to counteract the negative curvature induced by amyloid peptides , which in turn would decrease the likelihood of membrane fusion . This mechanism of action is thought to improve membrane stability, allowing the membrane and transmembrane proteins to maintain and recover the three-dimensional structure or folding for normal function such as membrane transport, chemical secretion, and receptor binding and stimulation .

Through restored membrane fluidity, piracetam promotes restored neurotransmission such as glutamatergic and cholinergic systems, enhances neuroplasticity and mediates neuroprotective and anticonvulsant effects at the neuronal level . It is also demonstrated that piracetam also improves the fluidity of platelet membranes. At the vascular level, piracetam decreases adhesion of erythrocytes to cell wall and reduces vasospasm which in turn improves microcirculation including cerebral and renal blood flow .

Dosage

Pirahenz dosage

Oral: Adults:

  • In cerebro-cortical insufficiency disorders, usual dose is one tablet (800 mg) 3 times a day.
  • In myoclonic seizures, a dose of 7.2 gm daily, increasing by 4.8 gm per day every 3 to 4 days up to maximum of 20 gm daily, given in 2 or 3 divided doses.

Oral: Children:

The daily dosage depends on the weight of the child, 50 mg/kg of body weight in 3 divided doses. Once the desired results has been obtained, reduce the initial dose by half.

Parenteral formulations: When parenteral administration is needed (e.g. swallowing difficulties, unconsciousness) Pirahenz can be administered intravenously.When treating severe symptoms, 12 g daily may need to be administered as an intravenous infusion.

Pirahenz is compatible (physico-chemical compatibility) with the perfusions of:

  • Glucose 5%, 10%, 20%
  • Fructose 5%, 10%, 20%
  • Sodium chloride 0.9%
  • Dextran 40 (10% in a 0.9% NaCl solution)
  • Ringer Mannitol 20%
  • HES solution (Hydroxy Ethyl Starch) 6% and 10%

The stability of these solutions has been demonstrated up to 24 hours.

Side Effects

The side effects reported include nervousness, agitation, irritability, anxiety and sleep disturbances. The incidence of these during clinical trials was (≤ 5%) and they were more often noted in the older patients taking > 2.4 gm daily. In the majority of cases, a dose reduction sufficed to make these symptoms disappear. Some patients may complain of fatigue or drowsiness, gastrointestinal problems, e.g. nausea, vomiting, diarrhoea and stomachache have also been reported but their incidence during clinical trials was ≤ 2%. Other symptoms e.g. vertigo, headache, trembling and sexual stimulation have occasionally been reported.

Toxicity

The cases of overdose with piracetam is rare. The highest reported overdose with piracetam was oral intake of 75g which was associated with diarrhea and abdominal pain; the signs were most likely related to the extreme high dose of sorbitol contained in the used formulation. In cases of acute, significant overdosage, stomach emptying by gastric lavage or induced emesis is recommended as there are no known antidotes for piracetam . Management for an overdose will most likely be symptomatic treatment and may include hemodialysis, where the extraction efficacy of the dialyser is 50 to 60% for the drug .

Oral LD50 in a mouse acute toxicity study was 2000 mg/kg .

Interaction

In a single case, confusion, irritability and sleep disorders were reported in concomitant use with thyroid extract. At present, no interaction has been observed with the following anti-epileptic drugs, clonazepam, carbamazepine, phenyton, phenobarbitone and sodium valporate, based on a small number of studies.

Volume of Distribution

Vd is approximately 0.6L/kg. Pirahenz may cross the blood-brain barrier as it was measured in the cerebrospinal fluid following intravenous administration . Pirahenz diffuses to all tissues except adipose tissues, crosses placental barrier and penetrates the membranes of isolated red blood cells .

Elimination Route

Pirahenz displays a linear and time-dependent pharmacokinetic properties with low intersubject variability over a large range of doses. Pirahenz is rapidly and extensively absorbed following oral administration with the peak plasma concentration is reached within 1 hour after dosing in fasted subjects. Following a single oral dose of 3.2 g piracetam, the peak plasma concentration (Cmax) was 84 µg/mL. Intake of food may decrease the Cmax by 17% and increase the time to reach Cmax (Tmax) from 1 to 1.5 hours. Tmax in the cerebrospinal fluid is achieved approximately 5 hours post-administration .

The absolute bioavailability of piracetam oral formulations is close to 100% and the steady state plasma concentrations are achieved within 3 days of dosing .

Half Life

The plasma half life of piracetam is approximately 5 hours following oral or intravenous administration. The half life in the cerebrospinal fluid was 8.5 hours .

Clearance

The apparent total body clearance is 80-90 mL/min .

Elimination Route

Pirahenz is predominantly excreted via renal elimination, where about 80-100% of the total dose is recovered in the urine. Approximately 90% of the dose of piracetam is excreted in the urine as unchanged drug .

Pregnancy & Breastfeeding use

Pirahenz should not be prescribed during pregnancy or when breast feeding, except under exceptional circumstances. Pirahenz is able to cross the placenta.

Contraindication

Pirahenz is contra-indicated in patients with severe renal insufficiency (creatinine clearance < 20 ml/min) and hepatic impairment. As the principal route of elimination for Pirahenz is via the kidney, special care must be taken when treating patients known to suffer from renal insufficiency. Monitoring of renal function is recommended in such cases. The increase in half-life is directly related to the decrease in renal function and creatinine clearance. This is also true for the older patient in whom creatinine clearance is dependent on age. When the creatinine clearance is < 60 ml/min, or serum creatinine is >1.25 mg/100 ml, the dosage prescribed should be calculated as following:

CrCl 60-40 ml/min: Dosage should be 1/2 of normal dose

CrCl 40-20 ml/min: Dosage should be 1/4 of normal dose

Special Warning

Children: No formal pharmacokinetic study has been conducted in children.

Elderly: In the elderly, the half-life of piracetam is increased and the increase is related to the decrease in renal function in this population (see Section Dosage and Administration).

Renal impairment: Pirahenz clearance is correlated to creatinine clearance. It is therefore recommended to adjust the daily dose of piracetam based on creatinine clearance in patients with renal impairment

Hepatic impairment: The influence of hepatic impairment on the pharmacokinetics of piracetam has not been evaluated. Because 80 to 100% of the dose is excreted in the urine as unchanged drug, hepatic impairment solely would not be expected to have a significant effect on piracetam elimination.

Acute Overdose

Pirahenz appears to be devoid of toxicity even at very high doses and, therefore, the need for specific measures to be taken in case of an overdose is avoided. Drug Interactions: In a single case, confusion, irritability and sleep disorders were reported in concomitant use with thyroid extract. At present, no interaction has been observed with the following anti-epileptic drugs, clonazepam, carbamazepine, phenytoin, phenobarbitone and sodium valproate, based on a small number of studies.

Storage Condition

Store in a cool and dry place at a temperature below 30˚C , Keep away from sunlight. Keep out of the reach of children.

Innovators Monograph

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FAQ

What is Pirahenz used for?

Pirahenz is most commonly used for breath-holding attacks, seizure disorder , dizziness, a learning disorder marked by difficulty reading , and a movement disorder often caused by antipsychotic drugs.

How safe is Pirahenz?

Pirahenz is considered safe with little risk of side effects. In long-term studies, doses of up to 24 grams daily have had no adverse effects.

How does Pirahenz work?

Pirahenz working by helped reduce the overall severity of myoclonic seizures.

How long does Pirahenz take to work?

Pirahenz is rapidly and extensively absorbed following oral administration with the peak plasma concentration is reached within 1 hour after dosing in fasted subjects.

What are the common side effects of Pirahenz?

Common side effects of Pirahenz include:

  • Diarrhea
  • Weight gain
  • Drowsiness
  • Insomnia
  • Nervousness
  • Depression
  • Muscle spasm
  • Hyperactivity
  • Rash

Is Pirahenz safe during pregnancy?

Pirahenz should not be used during pregnancy unless clearly necessary, when benefit exceeds the risks and the clinical condition of the pregnant mother requires treatment with Pirahenz.

Is Pirahenz safe during breastfeeding?

Pirahenz should not be used during breastfeeding or breastfeeding should be discontinued, while receiving treatment with Pirahenz.

Can I drink alcohol with Pirahenz?

Avoid Pirahenz alcohol while on treatment with this medicine.

Can I drink alcohol with Pirahenz?

Taking Pirahenz may cause drowsiness and shakiness. If this happens to you, please do not drive.

When should be taken of Pirahenz?

Pirahenz is usually taken two or three times daily. The normal starting dose is nine tablets.

Can I take Pirahenz everyday?

Pirahenz is considered safe with little risk of side effects. In long-term studies, doses of up to 24 grams daily have had no adverse effects.

How Pirahenz works in the brain?

Pirahenz improves the function of the neurotransmitter acetylcholine via muscarinic cholinergic receptors, which are implicated in memory processes.

How long does Pirahenz last?

The plasma half life of Pirahenz is approximately 5 hours following oral or intravenous administration.

Does Pirahenz raise blood pressure?

If you are taking Pirahenz you could be at risk for high blood pressure and heart problems.

Is Pirahenz good for anxiety?

Pirahenz significantly suppressed licking behaviour and this effect was evaluated as anxiogenic.

Can I take Pirahenz for a long time?

In long-term studies, doses of up to 24 grams daily have had no adverse effects.

Does Pirahenz increase dopamine?

Pirahenz increased the levels of dopamine metabolites.

What happens if I miss a dose of Pirahenz?

If you do forget to take a dose, take it as soon as you remember . Do not take two doses together to make up for a forgotten dose.

How much Pirahenz can I take?

 Pirahenz is usually taken two or three times daily. The normal starting dose is nine tablets (three tablets in the morning, three at midday and three in the evening).

Does Pirahenz affect sleep?

Pirahenz caused significant decreases in sleep latency and total wake time at a dose of 500 mg/kg.

*** Taking medicines without doctor's advice can cause long-term problems.
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