Prescriptions for Alzheimer's Disease

As many as 5.2 million Americans are afflicted with Alzheimer's disease. Named after the German psychiatrist, Alois Alzheimer, Alzheimer's disease is the most common form of dementia and is presently both incurable and degenerative. To make matters worse, unlike many other diseases or conditions, there are relatively few prescription medications available to help manage the symptoms and slow the progression of Alzheimer's disease. Care for Alzheimer's patients often falls upon the shoulders of a close loved-one or family member, and this article is designed to provide some information to assist them in this challenging and demanding responsibility.

As a pharmacist, I am often asked by concerned caretakers for information about medications for Alzheimer's disease. Questions about costs, side-effects, dosing schedules and drug interactions are among the chief concerns. My focus in this Hub is simply to provide a brief and focussed summary of the prescriptions medications used to treat Alzheimer's disease. The most frequent questions will be addressed, and links provided to websites with more detailed information for those who need it.

Currently, there are 5 prescription medications available for the treatment of Alzheimer's disease:

• Donepezil (Aricept & Aricept ODT & now ARICEPT 23!)
• Galantamine (Razadyne & Razadyn ER)
• Tacrine (Cognex)
• Rivastigmine (Exelon capsules, oral soluion & Exelon Patch)
• Memantine (Namenda & Namenda XR)

The first 4 drugs above work by a process known as "Cholinesterase Inhibition" and the last one, Namenda, works by a unique mechanism associated with what are known as NMDA receptors in the brain. These mechanisms are rather complicated, and uncertain, so it is not my intention to focus on explaining them here.

NEWS:

Some patients are wondering if combining Aricept with Namenda will provide better results than using either of these two products alone.

A recent study (March 2012) published in the New England Journal of Medicine suggests, unfortunately, that the combination of these two products does NOT provide better results than the use of either product alone. This means, at least based on this study, that if you or a loved one are on Aricept, adding Namenda is unlikely to provide more benefits.

Donepezil, which is marketed under the names of Aricept and Aricept ODT (which stands for 'orally disintegrating tablet'), is a cholinesterase inhibitor for the treatment of mild, moderate or severe symptoms of Alzheimer's Disease and manufactured by Pfizer pharmaceuticals.

History:

• 1996: First approved by FDA for treatment of mild to moderate Alzheimer's Disease
• 2004: Developed an orally distentegrating tablet for more easy administration of the medication
• 2006: Approved by the FDA for severe Alzheimer symptoms

Available Generically? Yes- except for 23mg (only the brand name is available for 23mg)

Dosage Forms and Strengths:

• Tablets: 5mg & 10mg
• ODT: 5mg & 10mg
• Aricept 23: A newly approved (June 2010) 23mg tablet of Aricept taken once daily with improved efficacy over the 10mg daily dosage. Note that nausea and vomitting are more common on this higher dosage than on other strengths. For more info on Aricept 23, CLICK HERE to go to the manufacturers website!

Side Effects: The side effects are more likely with the 10mg strength and include: loss of appetite, drowsiness, diarrhea, muscle crams, and nausea.

Dosage and Administration:

Taken once daily

More ways to save on prescription medications!

Galantamine, which is marketed under the names of Razadyne and Razadyne ER (which stands for "extended release"), is another medication for the treatment of Alzheimer's disease. Razadyne and Razadyne ER are products of Ortho-McNeil Pharmaceuticals and is approved to treat mild to moderate symptoms of Alzheimer's disease. On a side note, Razadyne was formerly marketed under the name "Reminyl" but was changed in 2005 due to similarity in name with a Diabetes drug (Amaryl) which resulted in 2 deaths when the Alzheimer's drug was mistakenly dispensed. However, the new name has the potential to be confused with a sleeping drug known as "Rozerem". What's in a name? Sometimes life or death. Look carefully at the prescription name on the bottle and read the literature that comes with it. Be sure it is not mistakenly filled with another drug.

History:

• 2001: Original FDA approval of Galantamine (then called "Reminyl")
• 2004: FDA approval of Razadyn ER, an extended release once-daily form

Available Generically? YES

Dosage Forms & Strengths:

• Tablets: 4mg, 8mg, and 12mg
• ER Tablets: 8mg, 16mg, 24mg
• Oral Solution: 4mg/ml (that is the equivalent of 20mg per teaspoonful)

Side Effects: As with Aricept, side effects tend to increase as the dosage goes up. The most frequent side effects are abdominal pain, diarrhea, dizziness, headache, tremor, depression, nausea and vomiting. This sounds like an intimidating list of potential problems! But nearly all of them occur less than 10% of the time. Often mild side effects can be managed by adjusting the dose.

Dosage & Administration:

• Tablets: Twice daily with food
• ER Tablets: Once daily in the morning, with food
• Oral Solution: Twice daily with food. Pay close attention to dosage! This is usually prescribed as 1ml, 2ml or 3ml per dose. Do NOT confuse "ml" with any other measurement...like "teaspoonfuls". One teaspoonful is equal to 5ml. Use a calibrated syringe (which should have been given to you) to measure. If you did not receive one, ask your local pharmacy to provide you with one.

For More Information:

• Taking Razadyne & Razadyne ER
• How to Save Money on Prescriptions

Tacrine, which is marketed under the name Cognex, is yet another prescription cholinesterase inhibitor for the treatment of Alzheimer's disease. Cognex was actually the first medication approved to improve cognitive function for Alzheimer's patients. Cognex is marketed by Sciele Pharma and received original FDA approval in 1993.

Available Generically? No

Dosage Forms and Strengths:

Capsules: 10mg, 20mg, 30mg and 40mg

Side Effects:

Nausea and vomiting are the most frequently reported side effects, and may occur in up to 20% of patients prescribed Cognex. Diarrhea occurs in approximately 1 in 10 patients. Other side effects include loss of appetite, myalgia (muscle pain), ataxia (loss of muscle coordination), dizziness and insomnia.

Dosage and Administration:

Cognex is typically started at 10mg given 4 times daily on (as best as possible) an empty stomach. It is ideally taken between meals and at bedtime. Due to the inconvenience of this dosing schedule, Cognex is not widely prescribed today.

For More Inforation:

Cognex Prescribing Information

Rivastigmine, marketed under the name Exelon, is approved to treat mild to moderate symptoms of Alzheimer's disease. As with the other prescription medications it will not improve the prognosis (outcome) of the disease, but may slow down the progression. Exelon is a Novartis Pharmaceutical product.

History:

• 2000: FDA approval of Exelon oral capsules and solution
• 2007: FDA approval of Exelon patch

Available Generically? The capsules have become available generically as of July 2010! This may be an opportunity to save a significant amount of money. If you are on the patch, talk to your doctor about switching to the generic oral capsules.

Dosage Forms and Strengths:

• Capsules: 1.5mg, 3mg, 4.5mg, 6mg
• Oral Solution: 2mg/ml
• Patches: 4.6mg/24 hours, 9.5mg/24 hours

Side Effects:

Nausea and vomiting are very common with the oral formulations, but much less likely with the patch when used at recommended doses. Other side effects include diarrhea, loss of appetite, stomach pain, dizziness, drowsiness, fatigue, headache and tremors.

Dosage and Administration:

Oral capsules and solution are given twice daily with food. The oral solution may be taken directly, or diluted in water or juice. Once diluted, it must be consumed within 4 hours.

Patches: Applied once daily to a clean, hairless area of the body (usually the chest or upper arm, but can also be applied by a caretaker to the upper or lower back). The patch site should be rotated daily to avoid skin irritation. Remove the patch and fold the sticky sides together and dispose. Apply new patch at the same time daily. Can be worn in shower, bath or pools.

For More Information:

• Official Exelon Patch Website
• Full Prescribing Info for Patch
• Patient Info for Exelon Patch
• How to Apply Exelon Patch

Memantine is a unique oral medication which has approved for the treatment of moderate to severe symptoms of Alzheimer's Disease and is markete by Forest Pharmaceuticalsin the U.S. Namenda gets its name from the fact that it acts as an antagonist of NMDA (N-methyl-D-aspartate) receptors.

History:

Namenda was approved for use in the U.S. by the FDA in October 2003

Prior to U.S. approval, memantine had been used in Germany to treat dementia since the 1980s.

Available Generically? No

Dosage Forms and Strengths:

• Tablets: 5mg, 10mg
• Oral Solution: 10mg/5ml
• COMING SOON: Namenda XR, a 28mg once-daily dose of Namenda, has been approved by the FDA in June 2010 and should be available shortly.

Side Effects:

Of all the medications available to treat Alzheimer's Disease, Namenda seems to be the best tolerated with the fewest side effects. In fact, in clinical trials, many side effects occurred more frequently with the placebo group, than in the Namenda group. Constipation, nausea, vomiting, and dry mouth were all reported, but in less than 5% of participants.

Dosage and Administration:

Dosage begins at 5mg once daily. This dose can be slowly increased over 4 weeks to a maximum dose of 10mg twice daily.

For More Information:

Official Namenda Website

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