Modafinil Dexamfetamine

SYMPATHOMIMETICS CNS STIMULANTS-MODAFINIL May l modafinil levels with dexamfetamine, methylphenidate Due to delayed absorption Be aware... 

In narcolepsy, patients usually need a stimulant for their hypersomnia and a TCA or SSRI for their cataplexy, so care should be taken when combining these. Dexamfetamine and methylphenidate must not be given with MAOIs. There is potential for interaction between methylphenidate and TCAs (hyperteirsion) and SSRI antidepressants. It appears that modafinil, methylphenidate and dexamfeta-mine may themselves be combined without adverse outcome (modafinil is occasionally used regularly and dexamfetamine added intermittently when peak alertness is particularly critical). Modafinil accelerates the metabolism of oral contraceptives, reducing their efficacy. 

In an open, randomized, crossover study in healthy men, concomitant administration of single oral doses of modafinil (200 mg) and dexamfetamine (10 mg), each given separately, produced a slight increase in blood pressure and the cardiovascular effects were more pronounced after concomitant administration (3). These changes were considered not to be clinically relevant and would not necessarily preclude shortterm administration of the two drugs together. The most frequent adverse events with modafinil or dexamfetamine were headache, dizziness, insomnia, and dry mouth. 

The potential for an interaction of modafinil with dexamfetamine, each at steady state, has been investigated in an open, randomized study in 32 healthy subjects (13). All took modafinil orally once daily for 28 days (200 mg on days 1-7 and 400 mg on days 8-28). On days 22-28, half of... 

No pharmacokinetic interaction appears to occur between modafinil and dexamfetamine. 

In a steady-state study, 23 healthy subjeets were given modafinil 200 mg daily for 7 days, followed by 400 mg daily for 3 weeks. During the last week, 10 of the subjeets were also given dexamfetamine 20 mg daily, 7 hours after their modafinil dose. Dexamfetamine eaused no significant change in the pharmacokinetics of modafinil and fhe combination was well tolerated. In addition, the pharmacokinetics of dexamfetamine did not appear to be affected by modafinil, when compared with values reported in the literature. Similar results were found in a single dose studyNo additional precautions appear to be necessary on concurrent use. 

---