Omeprazole: Uses, Dosage, Side Effects, & FAQs

How does omeprazole work?

It works by reducing the amount of acid produced in the stomach, making it effective in treating various acid-related conditions[1]. 

Who can take omeprazole?

Omeprazole can be taken by most adults and children over the age of one year. However, you should consult a doctor first if you have: 

• Liver disease 

• Osteoporosis or low bone mineral density 

• Low levels of magnesium in your blood 

• An endoscopy scheduled 

• Allergies to omeprazole or similar medications[2][4] 

How do you take omeprazole?

Omeprazole is usually taken once daily, preferably in the morning before a meal, in tablet or capsule form. It should be swallowed whole with water and not crushed or chewed. If you have difficulty swallowing capsules, you can open them and mix the contents with a small amount of applesauce[4][5].*

What is the typical dosage of omeprazole?

The typical dosage of omeprazole varies depending on the condition being treated: 

• Indigestion – 10mg to 20mg a day 

• Heartburn & acid reflux – 20mg to 40mg a day 

• GERD – 20mg once daily for 4-8 weeks 

• Stomach ulcers - 20mg to 40mg once daily  

• Zollinger-Ellison Syndrome - 20mg to 120mg once daily, adjusted as needed 

• H. pylori eradication - 20mg twice daily in combination with antibiotics for 7-10 days [5] 

What do you do if you take too much omeprazole?

It's very unlikely that one or two extra doses will cause you any problems. But if you suspect an overdose, seek immediate medical attention. Symptoms of overdose may include confusion, dizziness, drowsiness, diarrhoea, nausea, vomiting, abdominal pain and headache[6][7][13]. 

What do you do if you forget to take your omeprazole dose?

If you miss a daily dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and resume your regular schedule. If you usually take it twice a day, take the missed dose as soon as you remember, but if it’s 4 hours or less until your next, do not take it and take next dose as scheduled. Do not double the dose to catch up[8][9]. 

What are the side effects of omeprazole?

The most common side effects of Omeprazole include: 

• Headache 

• Nausea 

• Diarrhoea 

• Stomach pain 

• Gas 

• Vomiting[3][2] 

The most serious side effects of omeprazole, though rare, can include: 

• Severe allergic reactions (e.g., rash, itching, swelling) 

• Severe dizziness 

• Trouble breathing 

• Signs of kidney problems (e.g., change in the amount of urine) 

• Symptoms of a low magnesium blood levels (e.g., muscle cramps, irregular heartbeat)[3][2] 

If you experience any of these side effects, stop taking omeprazole and consult your GP or call 111. 

Medicines you can't take with omeprazole

Omeprazole can interact with several medications, including: 

• Warfarin - increases the risk of bleeding[10]. 

• Clopidogrel - reduces the effectiveness of this antiplatelet drug[11]. 

• Certain antifungals - such as ketoconazole and itraconazole[11]. 

• HIV medications - such as atazanavir and nelfinavir[11]. 

Always inform your healthcare provider about all the medications and supplements you are taking to avoid potential interactions. 

Frequently asked questions about omeprazole

Can I take omeprazole long-term? 

Long-term use of omeprazole should be monitored by a doctor or another healthcare provider due to potential risks such as vitamin B12 deficiency, magnesium deficiency, and bone fractures[12]. 

How long does it take for omeprazole to work? 

You should start to improve within two to three days, but it can take up to four weeks for omeprazole to work fully, and you may still have some acid symptoms in this period. 

If you don’t improve at all after two weeks, speak to your doctor or pharmacist. 

What if I’m not getting better using omeprazole? 

Speak to your doctor and pharmacist, who may consider different treatments, like pantoprazole or lansoprazole. 

Can I take antacids with omeprazole? 

Yes, antacids can be taken with omeprazole if needed[12]. 

Should I drive or cycle while taking omeprazole? 

It can cause dizziness, tiredness, and blurred vision. If you experience any of these symptoms, do not drive, cycle, or use heavy machinery. 

Can I drink alcohol and take omeprazole? 

Although alcohol doesn’t affect the way omeprazole works, you should try to avoid it where possible as alcohol makes your stomach produce more acid than normal. 

What else can I do improve my symptoms? 

Making lifestyle changes can help ease your symptoms. You should try to: 

• Maintain a healthy weight with a balanced diet 

• Avoid foods that cause excess acid, like rich, spicy, or fatty foods, and acidic foods, like citrus fruit, fizzy drinks, and salad dressings 

• Stop smoking  

• Reduce caffeine and alcohol consumption  

• Try not to eat 3 hours before you sleep 

• Prop your head and shoulders up when you sleep 

Is omeprazole safe during pregnancy? 

Consult your doctor before taking omeprazole during pregnancy[2]. 

Can I stop taking omeprazole? 

Is it usually safe to come off omeprazole without reducing your dose, but if you’ve been taking it for a while, speak to your doctor first. 

References

[1] About omeprazole - NHS  

[2] Omeprazole Uses, Side Effects, Dosage, Warnings - Drugs.com 

[3] Omeprazole Side Effects: Common, Severe, Long Term - Drugs.com 

[4] Omeprazole (oral route) - Mayo Clinic 

[5] Omeprazole Dosage Guide + Max Dose, Adjustments - Drugs.com 

[6] What Happens If You Overdose On Omeprazole - Statcare 

[7] Omeprazole overdose - wikidoc 

[8] How and when to take omeprazole - NHS 

[9] Omeprazole (Prilosec) Dosages: Forms, Max Dose, Adjustments - GoodRx 

[10] The 10 Omeprazole Interactions Everyone Should Know - GoodRx 

[11] Omeprazole Interactions Checker - Drugs.com 

[12] Omeprazole Patient Tips: 7 things you should know - Drugs.com 

[13] Omeprazole 20mg gastro-resistant Capsules – emc