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 | ||||||
| n = 189 | n = 63 | n = 39 | n = 93 | n = 278 | |||||||
| n | % | n | % | n | % | n | % | n | % | ||
| Pharmacokinetic interactions 1 | 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 2 | 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 3 | 13 | ||||||||||
| AII-blockers and diuretics | 13 | 6.9 | 13 | ||||||||
|
| |||||||||||
| Interactions in total | 107 | 24 | 19 | 1 | 206 | 357 | |||||
1Caused 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. 2With other CNS-active drugs resulting in a possibility for excessive adverse effects and sedation. 3Increased excretion of sodium and increased risk of hyponatremia with carbamazepine. ∗Also a pharmacokinetic interaction and included in Table 3.