Ebook Behavioural neurology of antiepileptic drugs: Part 2

(BQ) Part 1 book “Behavioural neurology of antiepileptic drugs “ has contents: Comparative evidence and clinical scenarios, phenobarbital and primidone, phenytoin, pregabalin, other antiepileptic drugs - rufinamide, lacosamide, perampanel,…and other contents.

Chapter Phenobarbital and primidone Phenobarbital and primidone are non-​proprietary first-​generation antiepileptic drugs (AEDs; Figs 9.–​9.3) Preparations Phenobarbital Tablets • Phenobarbital 5 mg (28-​tab pack £24.95) • Phenobarbital 30 mg (56-​tab pack £5.99) • Phenobarbital 60 mg (56-​tab pack £7.99) Oral solution Phenobarbital mg/​mL (500 mL £83.00) Primidone Tablets • Primidone 50 mg (00-​tab pack £70.00) • Primidone 250 mg (00-​tab pack £77.50) Generic formulation MHRA/​CHM advice is to minimize risk when switching patients with epilepsy between different manufacturers’ products (including generic products): • Category : doctors are advised to ensure that their patients are maintained on a specific manufacturer’s product Indications Epilepsy: monotherapy and adjunctive therapy of all seizures apart from focal seizures chapter 78 • behavioural neurology of antiepileptic drugs AEDs Brivaracetam Eslicarbazepine Zonisamide Pregabalin Levetiracetam Oxcarbazepine Tiagabine Topiramate Gabapentin Lamotrigine Vigabatrin Clobazam Piracetam Clonazepam Valproate Carbamazepine Ethosuximide Primidone Phenobarbital 1920 1930 Phenytoin 1940 1950 1960 1970 1980 1990 2000 2010 Fig 9.  Chronology of the clinical use of phenobarbital and primidone O H N O HN O Fig 9.2  Chemical structure of phenobarbital H N HN O Fig 9.3  Chemical structure of primidone chapter O year phenobarbital and primidone • 79 Phenobarbital Recommendations summarized from NICE (202) • Seizure types: on referral to tertiary care (focal seizures) • Epilepsy types: on referral to tertiary care (idiopathic generalized epilepsy, benign epilepsy with centrotemporal spikes, Panayiotopoulos syndrome, late-​onset childhood occipital epilepsy) Primidone Neurology: treatment of essential tremor Dose titration Phenobarbital Epilepsy: 60–​80 mg nocte Primidone Epilepsy—​monotherapy: 25 mg nocte, increased by 25 mg every days to 500 mg daily, divided into two doses, then increased by 250 mg every days; usual maintenance 75–​500 mg daily, divided into two doses Plasma levels monitoring Plasma phenobarbital concentration for optimum response is 5–​ 40 mg/​ L; however, monitoring the plasma concentration is less useful than with other drugs because tolerance occurs For primidone, it is possible to monitor plasma concentrations of derived phenobarbital as required Cautions • • • • Patients with a history of alcohol or drug abuse Elderly or debilitated patients Patients with acute porphyrias Patients with respiratory depression Adverse effects Phenobarbital can be associated with adverse effects at the level the nervous system and other systems (Table 9.) chapter 80 • behavioural neurology of antiepileptic drugs Table 9.  Estimated frequency of adverse effects of phenobarbital Very common or common (> in 0 or > in 00 patients on phenobarbital) Nervous system • amnesia • ataxia • behavioural disturbances • depression • drowsiness • hallucinations • impaired cognition • irritability • lethargy • nystagmus • paradoxical excitement and hyperactivity (especially in the elderly) Other systems • agranulocytosis • allergic skin reactions • anaemia • cholestasis • hepatitis • hypotension • osteomalacia • respiratory depression • thrombocytopenia Uncommon (> in 000 patients on phenobarbital) Nervous system Other systems Rare (> in 0,000 patients on phenobarbital) Nervous system • Psychosis Other systems • arthralgia • systemic lupus erythematosus Very rare ( in 0 or > in 00 patients on primidone) Nervous system • amnesia • ataxia • behavioural disturbances • depression • drowsiness • hallucinations • impaired cognition • irritability • lethargy • nystagmus • paradoxical excitement and hyperactivity (especially in the elderly) • visual disturbances Other systems • agranulocytosis • allergic skin reactions • anaemia • cholestasis • hepatitis • hypotension • nausea • osteomalacia • respiratory depression • thrombocytopenia Uncommon (> in 000 patients on primidone) Nervous system • dizziness • headache Other systems • vomiting Rare (> in 0,000 patients on primidone) Nervous system • psychosis Other systems • arthralgia systemic lupus erythematosus Very rare (