Does Duloxetine cause an upset stomach? (5+ tips)

In this article, we will talk about duloxetine-induced gastrointestinal problems along with other side effects. We will also discuss the research findings and factors which can contribute to gastric problems, along with precautionary measures and tips to prevent an upset stomach while taking duloxetine. 

Does Duloxetine cause an upset stomach? 

Yes, duloxetine can cause an upset stomach. Gastrointestinal problems are the common side effects seen with all the antidepressants. Duloxetine is a serotonin-norepinephrine reuptake inhibitor (SNRI) that inhibits reuptake receptors of serotonin and norepinephrine and increases their levels in the brain. (1)

This increase in serotonin and norepinephrine positively affects your mood, attention and energy level. Hence, duloxetine is used to treat depression and anxiety. Duloxetine also helps treat chronic pain by acting on neurons of the dorsal horn in the spinal cord. (1)

When duloxetine is used to treat pain, anxiety and depression, it is common to experience GI disturbance. However, these common side effects subsides as your body gets used to the drug. The symptoms of GI problems vary from person to person. 

If you are experiencing side effects for a longer period of time, consult your healthcare provider. Your physicain will suggest alternative therapy or decrease the dose of duloxetine. 

What does the research suggest? 

The common gastrointestinal side effects seen with duloxetine treatment were nausea, vomiting, decreased appetite, constipation, flatulence, abdominal pain and diarrhoea. (2) Clinical trials on duloxetine 40mg/day and 80mg/day compared with placebo reported that nausea was seen in 2.4% of patients treated with duloxetine, which was significantly higher than placebo. (3)

Side effects such as nausea, dizziness, vomiting, drowsiness, and loss of energy were the reasons for discontinuing duloxetine. (2,3) A case study reported duloxetine-induced lymphocytic colitis, in which a 50-year-old woman was admitted for complaints of mild abdominal pain, bloating and watery stools for 6 to 8 times a day. (4)

All other differential diagnoses were normal. The side effects were seen after six weeks of duloxetine treatment. When duloxetine was discontinued, the symptoms subsided within two weeks. (4)

One of the case studies reported that duloxetine can cause heartburn, which is a rare side effect. Post-marketing studies have shown that duloxetine can cause gastro-esophageal reflux disorder (GERD) in females above 60 years of age and in those individuals who are on long-term treatment with duloxetine. (5)

How does duloxetine cause an upset stomach?

Neurotransmitters such as serotonin, norepinephrine and dopamine have an effect on the gastrointestinal tract. An approximate 95% of serotonin is present in the GI tract. (6,7). An increased release of serotonin into the gut causes GI problems such as stomach upset. Fluctuations in these neurotransmitters affect the gut, causing symptoms like stomach upset. 

Since duloxetine acts by increasing the neurotransmitters, an increase in these neurotransmitters can enhance the occurrence of GI problems. Neurotransmitters are present throughout the human body and can cause other side effects such as: 

• Headache
• Drowsiness
• Fatigue
• Nausea
• Dry mouth
• Abdominal pain
• Insomnia
• Dizziness
• Tremor 
• Diarrhea
• Reduced appetite
• Erectile dysfunction

What are the factors that contribute to duloxetine-induced upset stomach?

There are a few factors which can contribute to GI problems along with the use of duloxetine. 

• Dietary: Foods which are spicy and high in fat can cause indigestion and irritation to the stomach lining, which can cause vomiting and nausea. Food like tomatoes, lemons and other acidic food can cause discomfort. 
• Overeating: Consuming a large quality of food in less time can burden your stomach, leading to abdominal pain.
• Disorders: Diseases such as GERD, Crohn’s disease, or inflammatory bowel disease can cause GI disturbances. Hence, it is important to get examined for any underlying disorder. 
• Drugs: Drugs such as NSAIDs and some antibiotics are said to cause GI bleeding and GI disturbances due to erosion of the protective layer of the stomach and irritation to the lining of the stomach. 
• Infections: H.pylori infection or any infection caused by bacteria or viruses can contribute to an upset stomach. 
• Stress and anxiety: Emotional distress can have a negative impact on the digestive system. 
• Food intolerance: If you are lactose intolerant, eating food such as gluten or lactose can cause nausea, vomiting or loose stools. Some of the drugs contain gluten, which can cause GI discomfort. 

How to minimise duloxetine-induced upset stomach? 

Duloxetine-induced GI disturbances, such as nausea, vomiting, diarrhoea, constipation, etc, usually subside after a few days of treatment as your body gets used to the drug. A study reported that 83% of individuals have upset stomachs till two weeks of treatment, and about 32% of individuals suffer till three months. (8)

The management of drug-induced nausea and vomiting can be achieved by taking the drug in divided doses or by taking the drug along with a small quantity of food. (8) Nausea and vomiting can be controlled by medication such as a proton pump inhibitor (Pantaprazole, omeprazole) or by drinking ginger tea. 

Management of diarrhoea includes drugs like loperamide and lactobacillus-containing tablets. Constipation can be treated with laxatives, stool softeners, etc. Common side effects can be managed easily, but if you are experiencing these side effects for months, seek medical attention. Your physician may decrease your dose or give you an alternative treatment. 

How do you ensure safe and effective use of duloxetine? 

Here are some tips for using duloxetine safely and effectively.

• Always take the dose as prescribed by the physician; do not increase or decrease your dose without guidance from your healthcare professional. 
• Take your medication at the same time every day. If you tend to forget, try setting up an alarm to remind you to take your drug.
• If you have insomnia after taking duloxetine, shift the dose to morning instead of night to avoid sleep problems. 
• If you are having an upset stomach, try taking the medication with food. 
• Avoid alcohol and limit your use of caffeine, as it can decrease the effectiveness of the medication. 
• Maintain a healthy lifestyle. A healthy body will react to the drug in a better way, and you will experience fewer side effects. 
• Stay hydrated,  as dehydration can decrease the elimination of the drug from your body and cause toxicity. 
• Know about the OTC medication which can interact with duloxetine and avoid taking it with the drug. 

In my experience, all antidepressants, including duloxetine, are associated with side effects. These common side effects usually subside as your body gets used to the drug and can be managed by drugs and by practising a few lifestyle changes.

If you are experiencing side effects which are affecting your day-to-day life activities, I would suggest you seek medical help. Your physician may change the drug or switch your drug to another antidepressant with fewer side effects. 

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