Drug therapies for Alzheimer's disease, have the ability to reduce functional and cognitive decline but don't necessarily work for all patients.
"I advocate treating early and as aggressively as possible," said Richard Ronald Finley, a clinical pharmacist at the University of California San Francisco, Memory and Aging Center & Alzheimer's Research Center. In drug therapy, research has shown that about one-third of the patients improve, one-third remain unchanged, and one-third become slightly worse "but better than expected with no treatment.... However, if you are looking for improvement in memory, you will be disappointed," Finley told the pharmacists.
The key drugs being given to patients are donepezil (Aricept, Eisai), rivastigmine (Exelon, Novartis), and galantamine (Razadyne, Janssen). Finley said he prefers donepezil, given in doses of 5 and 10 mg, because it may improve cognition and global function in patients with mild, moderate, or severe AD. Efficacy can be maintained for up to 50 weeks.
Rivastigmine, given in doses of 6 to 12 mg, may improve cognition and global function. While generally safe, it can cause cholinergic side effects at higher doses, Finley said. Galantamine can bring about a modest improvement in cognition, behavior, and function, and it is generally safe.
Finley noted that these three key drugs also have interactions with high anticholinergic drugs, belladonna alkaloids, tricyclic antidepressants, first-generation antihistamines, many skeletal muscle relaxants, drugs for urinary incontinence, many antipsychotic drugs, and some antiarrhythmic drugs.
Memantine (Namenda, Forest Laboratories), which is the newest drug, has brought about improvement for patients, Finley said. "Patients with moderately severe and severe AD benefited the most." The most common side effects reported in the clinical studies were dizziness, confusion, headache, and constipation.
When treating psychiatric behavioral issues related to dementia, Finley said it is important to pick the least hazardous drug and decide whether the patient's behavior is amenable to drug therapy. Some studies showed an increased incidence of heart problems in dementia patients treated with olanzapine (Zyprexa, Lilly) and risperidone (Risperdal, Janssen), which are antipsychotic medications.
Citing the results of a study reported in a newspaper, headlined "Antipsychotic drugs could increase the risk of death in the elderly," Finley pointed to a study of 22,890 patients treated with antipsychotic drugs between 1994 and 2003 in Pennsylvania. "Conventional antipsychotic medications were associated with a significantly higher adjusted risk of death than were atypical antipsychotic medications at all intervals studied," the article concluded.
On another issue, Mary Jo Carden, president of Carden & Associates, a health policy firm, addressed the legal and medical implications of drugs with black box warnings. Pharmacists are obligated to resolve implications of black box warnings before administering a drug-especially to the elderly, Carden said. In identifying irregularities, the pharmacist should consider whether the benefits outweigh the risks, the potential interactions with other drugs, and how the patient responds.
At the same time, pharmacists should not assume they cannot use a medication because of a black box warning. It is important to document the need for the medication relative to the black box warning, she emphasized.
Carden concluded that pharmacists are also required to document irregularities and report them to the attending physician or director of nursing.
THE AUTHOR is a writer based in Florida.