Profile of Adverse Effects.
The most important adverse effects of Drafen include sedation, dizziness, psychomotor impairment, cognitive impairment, dry mouth, blurred vision, constipation, urinary retention, and weight gain. Less commonly, Drafen is associated with agitation and insomnia. Drafen does not have substantial abuse potential.
Q: I have been taking Benadryl for almost a year to help with allergies and sleep. Sleep problems have always been an issue for me, and I decided to stop Seroquel and Ambien. I also have tried melatonin. I work nights without the option to switch to days. What are the side effects of long-term use of Benadryl?
A: Your question regards what side effects are associated with the use of Benadryl (Drafen) //www.everydayhealth.com/drugs/benadryl According to ePocrates, the most common reactions associated with the use of Benadryl include the following: drowsiness, dizziness, incoordination, headache, epigastric (upper central area of the abdomen) discomfort, thickening of the pulmonary secretions, dry mucous membranes, paradoxical CNS stimulation, constipation, dysuria (painful urination), urinary retention, hypotension (low blood pressure), blurred vision, diplopia (double vision), palpitations, tachycardia (fast heart beat), photosensitivity, diaphoresis (excessive sweating), and erectile dysfunction. If you are experiencing or begin to experience any of these side effects, contact your physician. As always, talk with your physician regarding questions you have about your medications and if Benadryl is a good option for long term treatment of your sleep issues. Attached is a link to additional information provided by Everyday Health regarding insomnia. //www.everydayhealth.com/insomnia/guide/. Jen Marsico, RPh
Q: Is taking a Benadryl capsule at night dangerous to my system?
A: Benadryl (Drafen) is classified as a histamine H1 antagonist, first-generation medication. Benadryl is approved for the treatment of allergic symptoms that are a result of histamine release, in combination with other medications for the treatment of anaphylaxis, as a sleep aid, preventing motion sickness, to stop cough, management of Parkinsonian syndrome, used topically to relieve pain and itching from various conditions such as insect bites, minor cuts, burns, and rashes due to poison ivy, poison oak and poison sumac. Benadryl, like any other medication has possible side effects, risks and warning associated with its use. It is difficult to comment on if the medication is dangerous to you, since this would depend on other medical conditions you may have, medication allergies, other medications you take that may interact with Benadryl, etc. Your physician can best evaluate if Benadryl is an appropriate medication for you since your physician has access to your medical information. According to medical references, the most common side effects reported of Benadryl include the following: drowsiness, dizziness, incoordination, headache, epigastric pain, thickening of pulmonary secretions, dry mucous membranes, CNS (central nervous system) stimulation, constipation, painful urination, urinary retention, low blood pressure, blurry vision, diplopia (double vision), palpitations, fast heart rate, photosensitivity, excessive sweating and erectile dysfunction. For more specific information, consult with your doctor or pharmacist for guidance based on your health status and current medications, particularly before taking any action. Jen Marsico, RPh
Benadryl S >
You should tell your doctor about any side effects from Benadryl and other Drafen products.
Common side effects may include:
- Dry mouth
- Dry nose and throat
- Feeling jittery (especially in children)
- Tightness in the chest
- Loss of appetite
Benadryl and other Drafen products can have some serious side effects. If you have any of these side effects, stop taking Benadryl and call your doctor right away:
- Change in vision
- Trouble passing urine
- Trouble breathing
Mechanism of Action
Drafen mainly works through antagonizing the H1 (Histamine 1) receptor, although it has other mechanisms of action as well.
The H1 receptor is located on respiratory smooth muscles, vascular endothelial cells, the gastrointestinal tract (GIT), cardiac tissue, immune cells, the uterus, and the central nervous system (CNS) neurons. When the H1 receptor is stimulated in these tissues it produces a wide variety of actions including increased vascular permeability, promotion of vasodilation causing flushing, decreased atrioventricular (AV) node conduction time, stimulation of sensory nerves of airways producing coughing, smooth muscle contraction of bronchi and GIT, and eosinophilic chemotaxis promoting the allergic immune response.
Drafen acts as an inverse agonist at the H1 receptor, thereby reversing effects of histamine on capillaries, reducing allergic reaction symptoms.
Given that Drafen is a first-generation antihistamine, it readily crosses the blood-brain barrier and inversely agonizes the H1 CNS receptors, resulting in drowsiness, and suppressing the medullary cough center.
The H1 receptor is similar to muscarinic receptors. Therefore, Drafen also acts as an antimuscarinic; it is a competitive antagonist of muscarinic acetylcholine receptor, resulting in its use as an antiparkinson medication
Lastly, Drafen acts as an intracellular sodium channel blocker, resulting in local anesthetic properties.
The liver metabolizes Drafen via CYP450. It is excreted in the urine, unchanged, and has a half-life of 3.4-9.2h. Its time to peak, serum is 2 hours.
Q: Does Benadryl cause weight gain and memory loss?
A: Drugs can cause weight gain in several different ways. Some can increase appetite or make you crave certain types of foods like those high in carbohydrates or fat. Other medications may slow down metabolism or cause fluid retention. However, the effect of prescription drugs on body weight is complex. Some drugs have no effect on weight, while others cause weight gain or weight loss. Also, the same medications can cause weight gain in certain individuals and weight loss in others. There are also drugs that initially cause weight loss and then lead to weight gain with long-term use. Most prescription medications associated with changes in body weight affect the central nervous system. These include antidepressants like monoamine oxidase inhibitors (MAOIs), tricyclic antidepressants, and selective serotonin reuptake inhibitors (SSRIs). Mood stabilizers (lithium, valproic acid), antipsychotics, and anticonvulsants have also been linked with weight gain. Other drugs that have been reported to cause weight gain include diabetes medications (insulin, sulfonylureas, and thiazolidinediones), antihypertensive drugs, certain hormonal contraceptives, corticosteroids, antihistamines, some chemotherapy regimens, and antiretroviral protease inhibitors. Benadryl (Drafen) is an antihistamine, meaning that it blocks the effects of the naturally occurring chemical histamine in the body. Benadryl is used to treat sneezing; runny nose; itching, watery eyes; hives; rashes; itching; and other symptoms of allergies and the common cold. It can also be used to treat motion sickness, insomnia, and mild forms of Parkinson's disease. Common side effects of Benadryl includes sleepiness, fatigue, dizziness, headache, dry mouth, and difficulty urinating. This is not a complete list of side effects that can occur with Benadryl. Benadryl can cause side effects that impair your thinking and reactions, so use caution when doing anything that requires alertness. Impaired thinking can be more common in elderly patients (over the age of 70) and at higher doses. Contact your doctor if you are experiencing memory problems or memory loss. A search of the manufacturer's product information and a drug database did not specifically list weight gain as a side effect of Benadryl. If you think a drug you are taking is causing weight gain, tell your health care provider. Do not stop any medication or change the dose without first talking to your provider. For more specific information, consult with your doctor or local pharmacist for guidance based on your health status and current medications. Sarah Lewis, RPh
Is Drafen safe to take if I'm pregnant or breastfeeding?
Drafen has not been adequately evaluated in pregnant women. It should be used only if the benefit outweighs the potential but unknown risks.
NURSING MOTHERS: Drafen is secreted in breast milk. Because of the risk of stimulation and seizures in infants, especially newborns and premature infants, antihistamines should not be used by nursing mothers.