Jessie50 asked
I am taking the weight loss drug Alli and wanted to know if it was safe to use it with Benadryl to help me sleep at night.
Answer
There are no known drug interactions between Alli and Benadryl. They are considered to be safe to take together.
Additionally, there should not be an increase in side effects if these medications are taken together as they have differing mechanisms of action, metabolism and side effect profiles.
Benadryl (Diphenhydramine)
Benadryl is an antihistamine, primarily used to treat allergic reactions. It can cause drowsiness and sedation which is why it is often used as a sleep aid. Benadryl’s ability to affect the CNS (central nervous system) and cause sedation is why it is not recommended in the elderly population. It can also cause constipation, urinary retention and dry mouth if taken consistently.
Each dose of Benadryl generally lasts 4 to 6 hours, with maximum effects occurring around 1 hour after dosing.
Alli
Alli (orlistat) inhibits the body from absorbing dietary fat and is used as a weight loss product. As this medications mechanism of action is inhibiting nutrient absorption, it is to be taken with meals. Since the fat taken up in the diet is not processed, it can cause stool to be oily and stomach side effects are typically the most common with this medication. Nausea and oily stools are generally more prominent when Alli is taken with high fat meals.
There have also been cases of severe liver injury with Alli’s use, and liver transplants have been required in some patients. As liver injury is a possible side effect, patients should monitor themselves for yellowing of their eyes and skin. If the patient does not experience more than 5% of body weight loss after 3 months of use, this product should be discontinued and another method tried instead.
Summary
- Benadryl (diphenhydramine) and Alli (orlistat) can safely be taken together. There is no interaction between the two medications.
