Neuropathies in HIV patients may warrant inclusion of anti-epileptics. Taking care  of drug interactions is noteworthy, confirms a study.

Team@CMHF

Although the evidence is weak, doctors should be aware that combining anti-HIV and anti-epileptic medications may lead to drug-on-drug interactions, according to a new guideline.

The issue is growing in importance as more and more people — especially in the developing world — are living with HIV as a chronic disease, according to Gretchen Birbeck, MD, of Michigan State

And up to 55% of people taking antiretroviral medications may need epilepsy control drugs at some point, although not for seizures in every case.

But, the authors noted, there are no formal guidelines to assist physicians in making drug choices. To help fill the gap, the American Academy of Neurology and the International League Against Epilepsy convened an international panel to sift through evidence and come up with guidelines.

The bad news, the panel found, was that the data are limited; only 42 articles yielded data, most of them reporting on Class II and Class III studies. As a result, the panel’s recommendations are all level C — any effect is only “possibly” valid.

Birbeck and colleagues noted that indications for anti-epileptic drugs have expanded beyond seizures to include such conditions as peripheral neuropathy and some psychiatric disorders.
But up to 11% of HIV patients may have seizure disorders and many more will suffer some form of peripheral neuropathy, leading to “substantial” concurrent use of anti-HIV and anti-epileptic medications worldwide, they argued.

The data analysis found that some combinations may need dose adjustments:

• Patients receiving phenytoin (Dilantin) may need about a 50% increase in the dosage of lopinavir/ritonavir (Kaletra) to maintain serum concentrations at the right level
• Patients taking valproic acid may need a lower dose of zidovudine (AZT) to keep serum concentrations unchanged
• Patients receiving atazanavir/ritonavir (Reyataz/Norvir) may require about a 50% increase in the dose of lamotrigine (Lamictal) to keep serum concentrations unchanged

On the other hand, the limited evidence suggests that:

• Using atazanavir or raltegravir (Isentress) with lamotrigine may not require lamotrigine dosage adjustment
• Giving raltegravir and midazolam together may not require adjusting the midazolam dosage
• Using valproic acid and efavirenz (Sustiva) may not require efavirenz dosage adjustment

It also may be important to avoid enzyme-inducing anti-epileptics for people whose HIV regimens include protease inhibitors or non-nucleoside reverse transcriptase inhibitors, the panel found.
“It is important that patients know exactly which drugs they are taking and provide that information to all prescribing health care providers caring for them,” Birbeck said in a statement. “Doctors may need to watch and adjust drug doses in people with HIV/AIDS who take seizure drugs.”

Ref: http://www.medpagetoday.com/Neurology/Seizures/30489?utm_medium=email&utm_campaign=DailyHeadlines&utm_source=WC&email=drsumanrao21@gmail.com&eun=g371326d0r&userid=371326&mu_id=