Prevalence of Different Combinations of Antiepileptic Drugs and CNS Drugs in Elderly Home Care Service and Nursing Home Patients in Norway

Table 4

Other identified drug-drug interactions involving antiepileptic drugs in patients ≥65 years receiving home cares services or living in nursing homes.

	Antiepileptic drugs
	Carbamazepine		Phenobarbital		Phenytoin		Valproic acid		Pregabalin or gabapentin		Total
		%		%		%		%		%
Pharmacokinetic interactions												79
Amlodipine	19	10.0	4	6.3							23
Atorvastatin			3	4.8							3
Simvastatin	31	16.4			4	10.3					35
Folic acid					5	12.8					5
Zopiclone			9	14.3	4	10.3					13
Pharmacodynamic interactions											265
Benzodiazepines					4	10.3			49	17.6	53
Fluoxetine							1	1.1			1
Mianserin	13	6.9	2	3.2	2	5.1					17
Opioids			6	9.5					79	28.4	85
Zopiclone	31	16.4							78	28.1	109
Other interactions											13
AII-blockers and diuretics	13	6.9									13
Interactions in total	107		24		19		1		206		357

Caused by combination with AED enzyme inducers or inhibitors causing a decrease in serum concentration and lack of efficacy of the affected drug or an increase in serum concentration and excessive adverse effects or toxicity, respectively. With other CNS-active drugs resulting in a possibility for excessive adverse effects and sedation. Increased excretion of sodium and increased risk of hyponatremia with carbamazepine. Also a pharmacokinetic interaction and included in Table 3.