Primidone
Also known as: Hexamidinum, Primaclone
Primidone is a derivative of barbituric acid. Primidone is a 2-desoxyphenobarbital, was first marketed in the early 1950s. It resembles phenobarbital in its anticonvulsant activity.
Primary Characteristics
Primidone is also known as Hexamidinum, Primaclone.
It is of Synthetic origin and belongs to Pyrimidine.
It belongs to Anticonjuctivitis pharmacological group on the basis of mechanism of action and also classified in Antipsychotic Agent pharmacological group.
Molecular Weight: 218.3 · pKa: not relevant · Solubility in Water: 1 in 2000 · Solubility in Alcohol: 1 in 170 · Non-proprietary name: Primidone.
Pharmacokinetics
Absorption: Primidone has an oral bioavailability is 80% (±5%), pre-systemic (first-pass) metabolism accounts for 0.5% (±0.5%).
Distribution: Primidone has a volume of distribution is 0.6 l/kg. plasma protein binding is 35 %.
Elimination: plasma half-life is 4 - 22 hr, renal excretion is > 5 %.
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Indications
Primidone is primarily indicated in conditions like Epilepsy, Essential tumor.
Contraindications
Primidone is contraindicated in conditions like Porphyrias.
Dosage
Primidone's dosage details are as follows:
| Dose | Single Dose | Frequency | Route | Instructions |
|---|---|---|---|---|
| Adult Dosage | ||||
| 1.61 mg/kg | 1.61 mg/kg | — | PO | Initially for 9 Days |
| 3.57 mg/kg | 3.57 mg/kg | Every 8h | PO | Maintenance |
| Paediatric Dosage (20kg) | ||||
| 5 mg/kg | 5 mg/kg | Every 24h | Oral | Initially at Bed time |
| 12.5 mg/kg | 12.5 mg/kg | Every 12h | Oral | Maintenance, As Required |
| Neonatal Dosage (3kg) | ||||
| 5 mg/kg | 5 mg/kg | Every 24h | Oral | Initially at Bed time |
| 12.5 mg/kg | 12.5 mg/kg | Every 12h | Oral | Maintenance, As Required |
Drug Interactions
Always consult your physician for the change of dose regimen or an alternative drug of choice that may strictly be required.
Side Effects
Primidone in overdosage may give rise to further complications which include Ataxia , Drowsiness , Nausea , Vertigo , Vomiting .
Primidone produces potentially life-threatening effects which include Lupus erythematosus, Hepatitis , Dermatitis bullosa striata pratensis. Careful monitoring is needed with proper medical management.
The signs and symptoms that are produced after acute overdosage of Primidone are Crystalluria , CNS depression, Depression of deep tendon reflexes, Flaccidity .
Primidone is known to cause more or less tolerable side effects which are usually transient. These include Ataxia, Impotence, Irritability, Loss of libido, Loss of memory, Nystagmus , Sleepiness, Tremors.
Warnings / Precautions
Interference in Pathology
Primidone may interfere in the diagnosis of Measurement of Urinary Pregnanediol by Gas Chromatographic Method .
Available Brands
None recorded.
Storage Conditions
Drug Classification
- 1.5 — Anticonvulsants and Antiepileptics