Prescription required

Ctd O 12.5/20 — Side Effects & Warnings

Known side effects of Ctd O 12.5/20 include Nausea Taste change Diarrhea Stomach upset Weakness Headache Dizziness Increased blood uric acid Increased blood lipid level Electrolyte imbalance Glucose intolerance Decreased blood pressure. Not everyone experiences these side effects.

Medically reviewed by Dr. Balaji Krishnan, MBBS · Updated June 2026

Common Side Effects

Nausea Taste change Diarrhea Stomach upset Weakness Headache Dizziness Increased blood uric acid Increased blood lipid level Electrolyte imbalance Glucose intolerance Decreased blood pressure

This is not an exhaustive list. Consult your doctor if you notice any unusual symptoms.

Pregnancy Safety

CTD-O 12.5/20 Tablet is unsafe to use during pregnancy.<br>There is positive evidence of human fetal risk, but the benefits from use in pregnant women may be acceptable despite the risk, for example in life-threatening situations. Please consult your doctor.

Alcohol Interaction

Taking Chlorthalidone with alcohol may have additive effects in lowering your blood pressure. You may experience headache, dizziness, lightheadedness, fainting, and/or changes in pulse or heart rate.

Ctd O 12.5/20 — Safety Summary

Composition: Olmesartan (20mg) + Chlorthalidone (12.5mg)
Prescription: Required (Rx)
Pregnancy: CTD-O 12.5/20 Tablet is unsafe to use during pregnancy.<br>There is positive evidence of human fetal risk, but the benefits from use in pregnant women may be acceptable despite the risk, for example in life-threatening situations. Please consult your doctor.
Alcohol: Taking Chlorthalidone with alcohol may have additive effects in lowering your blood pressure. You may experience headache, dizziness, lightheadedness, fainting, and/or changes in pulse or heart rate.

Ctd O 12.5/20 — Safety FAQs

What should I do if I experience side effects?

Mild side effects often resolve on their own. If side effects are severe or persistent, stop the medicine and consult your doctor immediately.

Are all listed side effects common?

No. Some side effects are common while others are rare. Not everyone experiences side effects. Consult your doctor if you are concerned.

Can I take this medicine with other drugs?

Some medicines interact with each other. Always inform your doctor about all medicines you are currently taking.

When should I seek emergency help?

Seek immediate medical attention if you experience severe allergic reactions (difficulty breathing, swelling of face/throat), chest pain, or any life-threatening symptoms.

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Safety disclaimer

This information is for educational purposes only and is not a substitute for professional medical advice. If you experience severe side effects, seek medical attention immediately.

Ctd O 12.5/20 — Side Effects & Warnings

Medically reviewed by Dr. Balaji Krishnan, MBBS · Updated June 2026