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Dicyclomine interactions to avoid

To avoid potentially dangerous side effects, it is important to know that dicyclomine interacts with certain diuretics, anticonvulsants, pain medication, dementia treatments, potassium supplements, and cannabinoids
By | Jan. 9, 2024
Three Rx pill bottles: Dicyclomine interactions

Key takeaways

  • Doubling up on drugs with anticholinergic actions is dangerous. Besides intestinal antispasmodics like dicyclomine, these drugs come in the form of inhalers for chronic obstructive pulmonary disease (COPD) and pills for overactive bladder and allergies.

  • Dicyclomine can amplify the adverse effect potential of thiazide diuretics, the anticonvulsant topiramate, opioid pain relievers, potassium supplements, and cannabinoids.

  • By increasing brain levels of the neurotransmitter acetylcholine, acetylcholinesterase inhibitors are an important treatment for Alzheimer’s disease (AD). Still, if taken together with anticholinergics, the two drugs cancel out the effectiveness of one another.

  • Dicyclomine and other anticholinergics can be very troublesome in the setting of certain health conditions involving the eye, nervous system, intestine, or bladder.

  • Anticholinergic side effects of dicyclomine are no minor matter, so if you are experiencing any or feel you are at risk due to drug interaction, contact your healthcare provider immediately.

In this article:

Relief from the abdominal pain and cramping of irritable bowel syndrome (IBS) can come in the form of dicyclomine tablets. The medication belongs to the anticholinergics class, but more specifically, it functions as an antispasmodic in IBS, relaxing smooth muscle spasms of the intestinal tract. As appealing as that sounds for sufferers of IBS pain, the drug’s anticholinergic side effects, like dry mouth, dry skin, constipation, drowsiness, and blurred vision, are not the only cautionary tales to be aware of. Dicyclomine, also known by the brand name Bentyl, interacts with other anticholinergic treatments, which come from a range of different areas of healthcare. Besides learning how to avoid additive anticholinergic side effects, it is important to understand dicyclomine’s important interactions with certain diuretics, anticonvulsants, pain medication, dementia treatments, potassium supplements, and cannabinoids.

Dicyclomine drug interactions

The majority of what you need to watch out for is medication side effects that dicyclomine can magnify. Reduction in the effectiveness of cholinesterase inhibitors is noteworthy, too.

Inhaled muscarinic antagonists

Spasms of the smooth muscle around bronchial tubes can be the bane of COPD by producing wheezing, cough, and shortness of breath. This spasm is relieved by inhaled antispasmodic agents, such as beta-agonists and muscarinic antagonists. The latter class does so by an anticholinergic mechanism. Coupled with dicyclomine, anticholinergic side effects can accumulate, namely constipation, dry mouth, drowsiness, difficulty urinating, and blurred vision.

Examples of muscarinic antagonists to avoid or speak to the prescriber about include:

Oral muscarinic antagonists

The bladder is also powered by smooth muscle, and if that muscle is prone to spasms, an overactive bladder can result. Accordingly, muscarinic antagonists can help by relaxing the bladder muscle. The same problems exist with oral as with inhaled muscarinic antagonists when it comes to interactions with dicyclomine. Even the injectable antimuscarinic drug atropine can be a problem. Avoid the drug pairing or watch out for anticholinergic side effects when taking dicyclomine with muscarinic antagonists like the following:

Diphenhydramine

Better known as brand-name Benadryl, diphenhydramine is an antihistamine, but it has anticholinergic effects too. As you now know, that can be a problem for those who take dicyclomine. Duplicative anticholinergics can make you feel tired, dry, and constipated. This is a good example of why you should ask your healthcare provider before taking a new over-the-counter medication like diphenhydramine.

You are probably getting the picture by now that anticholinergics come in many flavors. More evidence is that the Parkinson’s disease drug amantadine and tricyclic antidepressants, like amitriptyline, are also on the list of anticholinergics.

Antipsychotics

In addition to utility for psychotic disorders, antipsychotics are also useful for mood disorders like depression and bipolar disorder. Part of their mechanism of action is an anticholinergic one. Therefore, double-check with the prescriber or pharmacist before taking dicyclomine along with antipsychotics, such as the following:

Potassium supplements

Taking extra potassium may seem innocuous, but it is certainly not. Potassium chloride and potassium citrate can be hard on the stomach, even irritating the lining enough to cause ulcers. By slowing down the stomach’s emptying and increasing the amount of time that potassium pills sit in the stomach, dicyclomine can intensify that irritation and raise the risk of stomach ulceration. Check with your doctor before taking this combination; typically, it is avoided.

Thiazide diuretics

Slowing gastrointestinal action with dicyclomine can give other medications more time to be absorbed, hence heightening their potency. Thiazide diuretics are an example of this. This class is a popular pick for hypertension management. Still, besides being effective for reducing high blood pressure, they can also help to eliminate excess fluid swelling through their diuretic action. Too much of these actions could lead to dehydration or hypotension (low blood pressure), so medical professionals usually urge caution with or avoidance of dicyclomine when taking a thiazide-like:

Opioid agonists

Opioids are strong pain relievers. Their adverse effects include sedation, constipation, and difficulty urinating. Sound familiar? The overlapping side effects of opioid agonists and dicyclomine mean that those particular adverse effects are much more likely. Get the medical advice of your healthcare team to determine what to watch for if taking dicyclomine with opioids, such as:

Topamax

Topamax (topiramate) is used as an anticonvulsant for epilepsy or as a preventive medication for migraine headaches. One of its unique potential side effects is hyperthermia or fever. Considering that reduced sweating is one effect of anticholinergics, dicyclomine can raise one’s risk of overheating and heat stroke. The combination of Topamax and dicyclomine can be a hazardous combination when it comes to body temperature regulation, something that is more concerning in the setting of physical activity or hot weather. If both medications are necessary, ask one of the prescribing healthcare professionals how to keep yourself safe from this danger.

Cholinesterase inhibitors

Reduced acetylcholine levels are a feature of Alzheimer’s dementia, and the cholinesterase inhibitor drug class addresses this deficit by reducing the breakdown of the neurotransmitter. Conversely, anticholinergics block the effect of acetylcholine, making meds like dicyclomine problematic when looking for the maximal effectiveness of cholinesterase inhibitors, like Aricept (donepezil) and galantamine. In fact, dicyclomine and other anticholinergics are often avoided in older adults due to a higher risk of side effects.

Dicyclomine food interactions

Dicyclomine can be taken with or without food. No particular food interaction exists. However, by reducing stomach emptying, food can sit in your stomach longer when taking dicyclomine, and this can result in more reflux symptoms and heartburn. Eating smaller meals and not lying down after a meal may help if you experience more gastroesophageal reflux when taking dicyclomine.

Other dicyclomine interactions

Dicyclomine can exacerbate other health conditions. Its interaction with cannabinoid products is another point of note.

Dicyclomine and cannabinoids

Tetrahydrocannabinol and cannabidiol are types of cannabinoids found in marijuana and various medicinal and edible products. Their negative attributes include a propensity for elevating heart rate and blood pressure, and anticholinergics like dicyclomine can enhance this adverse effect. Clearly, it would help if you told your medical providers everything you are taking and using.

Dicyclomine and myasthenia gravis

At the root of muscle weakness in myasthenia gravis is impaired acetylcholine activity. The use of anticholinergics is contraindicated in the disease because further reducing cholinergic activity could severely exacerbate muscle weakness. Consequently, dicyclomine is generally not taken with myasthenia gravis.

Dicyclomine and glaucoma

Glaucoma raises pressure within the eye and can lead to vision loss. One form of the disease, called angle-closure glaucoma, can be precipitated by anticholinergic drugs like dicyclomine. If you have a history of angle-closure glaucoma, your providers will likely steer you clear of dicyclomine due to this contraindication.

Dicyclomine and severe ulcerative colitis

Ulcerative colitis (UC) is an inflammatory bowel disease marked by varying degrees of swelling and ulceration of the colon. Those with UC can experience abdominal pain, diarrhea, and bloody stool, among other intestinal and extraintestinal symptoms. Slowing down intestinal movement can amplify the action of inflammatory mediators, even leading to a critical illness called megacolon in some cases. Talk to your healthcare team about whether to avoid or exercise caution with dicyclomine in the setting of ulcerative colitis.

Dicyclomine and urinary or intestinal obstruction

Putting the breaks on the intestinal tract or bladder with anticholinergics, including dicyclomine, can be problematic. Constipation or urinary retention can occur. Intestinal blockage, an enlarged prostate, and the presence of a colostomy are all scenarios in which your doctor may exercise greater caution before prescribing dicyclomine or downright avoid it altogether.

Dicyclomine and breastfeeding

Dicyclomine is contraindicated in breastfeeding moms. For one, it can reduce lactation, but more importantly, it is found in breast milk and could lead to serious side effects in infants, such as apnea or cessation of breathing.

How to minimize dicyclomine interactions

Communication is key to keeping medicines safe. Keep a current list of prescription drugs, over-the-counter medications, and supplements. Have a record of your medical problems. On a regular basis, share this information with your medical providers and pharmacists. Hopefully, these actions will prevent an interaction. On the other hand, knowing what side effects to watch for with your medications is critical so that you can report any symptoms to your healthcare team right away.

When to talk to a healthcare provider about dicyclomine interactions

Reaching out to your healthcare provider is an urgent matter if you develop symptoms of a dicyclomine interaction. This could be anything from blurred vision to abdominal pain. Ideally, you want to have a conversation about drug interactions anytime a new medication is prescribed or you are considering taking a new over-the-counter product. The interactions discussed here highlight some of the dicyclomine’s important interactions, but the list is more extensive than what is presented. By asking directly about whether dicyclomine or the new drug could create a problem based on your med list or medical history, you can improve the safety of your medical care.

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