I was prescribed clonidine 0.1 mg three times daily as needed for 7 days, but the pharmacy gave me a glipizide 2.5 mg/metformin 250 mg combination tablet instead. What should I do?

Immediate Action Required: Pharmacy Dispensing Error

Stop taking the glipizide/metformin combination pill immediately and contact the pharmacy to obtain the correct clonidine 0.1 mg prescription—do not take any more doses of the wrong medication. 1, 2

Understanding the Dispensing Error

This is a serious pharmacy dispensing error where you received an antidiabetic medication (glipizide 2.5 mg/metformin 250 mg) instead of an antihypertensive medication (clonidine 0.1 mg). 1, 3

Key differences between what you should have received versus what you got:

• Clonidine 0.1 mg: A central alpha-2 agonist used for blood pressure control, ADHD, or other conditions requiring sympathetic nervous system suppression 4
• Glipizide/Metformin: A combination antidiabetic medication that lowers blood sugar—glipizide stimulates insulin release from the pancreas (sulfonylurea class) and metformin reduces glucose production in the liver 5

Immediate Steps to Take

1. Stop the Wrong Medication Now

If you do not have diabetes, taking glipizide/metformin can cause dangerous hypoglycemia (low blood sugar). 5

• Glipizide causes your pancreas to release insulin even when blood sugar is normal, which can drop glucose to dangerously low levels 5
• Symptoms of hypoglycemia include shakiness, sweating, confusion, rapid heartbeat, dizziness, and in severe cases, loss of consciousness 5

2. Monitor for Hypoglycemia Symptoms

If you have taken any doses of the glipizide/metformin, watch for hypoglycemia symptoms for the next 12-24 hours: 5, 6

• Check blood glucose if possible (normal range: 70-100 mg/dL fasting)
• If symptoms occur, consume 15-20 grams of fast-acting carbohydrates (juice, glucose tablets, regular soda)
• Seek emergency care if symptoms are severe or persistent 5

3. Contact the Pharmacy Immediately

Call the pharmacy that dispensed the medication and inform them of the dispensing error: 1, 2

• Request the correct clonidine 0.1 mg prescription be filled immediately
• Ask them to document this error in their quality assurance system
• The pharmacy should provide the correct medication at no additional cost 2

4. Notify Your Prescribing Physician

Contact the physician who prescribed clonidine to inform them: 3, 6

• You have not received any doses of clonidine as prescribed
• You may have taken doses of an antidiabetic medication instead
• Determine if you need to restart the 7-day clonidine course or if the indication has resolved 4

Critical Clonidine Considerations

If You Haven't Started Clonidine Yet

Since you never actually took clonidine, there is no withdrawal risk—you can safely start it once you obtain the correct medication. 4, 7

• Begin with 0.1 mg as prescribed (likely three times daily based on your prescription) 4, 8
• Monitor blood pressure and heart rate during treatment 8
• Common side effects include sedation, dry mouth, and dizziness 4, 8

Important Clonidine Safety Information

Never stop clonidine abruptly once you start taking it—this can cause severe rebound hypertension (dangerously high blood pressure). 4, 7

• Even for a 7-day course, taper the medication if discontinuing (reduce dose gradually over 2-4 days minimum) 4, 7
• Rebound hypertension can occur within 12-48 hours of abrupt cessation 4
• Symptoms include nervousness, agitation, headache, rapid blood pressure rise, and in rare cases, stroke 4

Documentation and Follow-Up

Request written documentation of this dispensing error for your records: 1, 6

• This protects you if any adverse effects occurred from taking the wrong medication
• Medication errors should be reported to improve pharmacy safety systems 1, 2
• Consider filing a report with your state board of pharmacy if the pharmacy does not take the error seriously 6

Common Pitfalls to Avoid

Do not assume the pharmacy will automatically know about the error—you must actively contact them. 2, 6

Do not continue taking the glipizide/metformin "just to finish the prescription"—this is dangerous if you don't have diabetes. 5

Do not start clonidine without confirming the indication is still present—if the 7-day window has passed, check with your physician first. 4, 8

If you do start clonidine, do not stop it suddenly even after 7 days—taper the dose over 2-4 days minimum. 4, 7