Patient prescribed clonidine 0.1 mg three times daily (TID) as needed (PRN) for 7 days was mistakenly dispensed a glipizide 2.5 mg/metformin 250 mg combination tablet; what steps should be taken to correct the dispensing error and manage possible hypoglycemia and uncontrolled hypertension?

Immediate Management of Pharmacy Dispensing Error: Glipizide/Metformin Given Instead of Clonidine

Stop the glipizide/metformin combination immediately, assess for hypoglycemia with urgent fingerstick glucose and treat if present, then address the missed clonidine doses to prevent rebound hypertensive crisis. 1

Immediate Actions for Hypoglycemia Risk

Assess Blood Glucose NOW

• Check fingerstick glucose immediately – glipizide 2.5 mg causes hypoglycemia by stimulating pancreatic insulin release, and the patient has been taking this incorrectly for up to 7 days (21 doses if taken TID). 1
• Severe hypoglycemia (glucose <70 mg/dL with symptoms or <54 mg/dL) requires aggressive treatment with oral glucose 15-20 grams if conscious, or IV dextrose 50% (25-50 mL) if altered mental status or unable to take oral. 1
• Monitor for 24-48 hours minimum even after apparent recovery, as sulfonylurea-induced hypoglycemia frequently recurs due to the drug's prolonged half-life. 1

Symptomatic Management

• Mild hypoglycemia without neurological impairment: treat with oral glucose (juice, glucose tablets) and recheck glucose every 15 minutes until >100 mg/dL. 1
• Severe hypoglycemia with coma, seizure, or neurological symptoms: this is a medical emergency requiring immediate hospitalization, rapid IV injection of 50% dextrose, followed by continuous 10% dextrose infusion to maintain glucose >100 mg/dL. 1

Critical Clonidine Withdrawal Management

Rebound Hypertension Risk

Abrupt clonidine discontinuation is potentially harmful and can precipitate severe hypertensive crisis with symptoms including nervousness, agitation, headache, tremor, and rapid blood pressure elevation. 2, 3, 4

Immediate Assessment

• Measure blood pressure and heart rate immediately to establish baseline and assess for early rebound hypertension (SBP >180 mmHg or DBP >110 mmHg indicates severe elevation). 2, 3
• The patient has missed 7 days of clonidine (potentially 21 doses if prescribed TID), placing them at extremely high risk for withdrawal syndrome. 2

Reinitiation Strategy

• Resume clonidine 0.1 mg immediately at the prescribed TID schedule to prevent further withdrawal progression. 3, 4
• If blood pressure is already severely elevated (≥180/110 mmHg), consider giving the first dose stat and monitoring BP every 30-60 minutes. 5
• Do NOT use oral clonidine loading (multiple doses in rapid succession) unless this is a true hypertensive emergency with end-organ damage, as the patient was only on 0.1 mg TID PRN baseline. 5

Monitoring Protocol

First 24-48 Hours

• Check blood glucose every 2-4 hours for the first 24 hours, then every 4-6 hours for an additional 24 hours, as glipizide-induced hypoglycemia can recur even after apparent recovery. 1
• Monitor blood pressure and heart rate every 4 hours for the first 48 hours after restarting clonidine to assess for both rebound hypertension and excessive BP lowering. 3, 6
• Hold clonidine if SBP <90 mmHg, DBP <60 mmHg, or heart rate <50 bpm to prevent symptomatic hypotension or bradycardia. 3, 6

Ongoing Surveillance

• Assess for orthostatic hypotension (measure BP supine and after standing 1-3 minutes) as clonidine increases this risk, particularly if the patient is elderly. 3, 6
• Watch for clonidine CNS effects: sedation, drowsiness, dizziness, dry mouth, and confusion, which are common and may be pronounced after reinitiation. 3, 4

Pharmacy Error Documentation and Prevention

Immediate Reporting

• Report this dispensing error to the pharmacy immediately and request they retrieve all remaining medication to prevent continued wrong medication administration. 7, 8, 9
• Document the error in the medical record including: dates of incorrect medication administration, total doses taken, patient symptoms, and clinical findings. 7, 8, 9
• File a medication error report with your institution's patient safety system and consider reporting to the state board of pharmacy, as compounding and dispensing errors can cause severe harm or death. 7, 8, 9

Patient Education

• Instruct the patient to bring ALL medications to appointments and verify pill appearance matches the prescription label, as visual inspection can catch dispensing errors. 7, 8, 9
• Teach recognition of hypoglycemia symptoms: shakiness, sweating, confusion, rapid heartbeat, hunger, and the need for immediate glucose intake. 1
• Warn about clonidine withdrawal symptoms: severe headache, rapid BP rise, agitation, tremor, and the absolute necessity of never missing doses or stopping abruptly. 2, 4

Common Pitfalls to Avoid

• Do NOT assume the patient is "fine" if asymptomatic – sulfonylurea hypoglycemia can be delayed and severe, requiring extended monitoring even without initial symptoms. 1
• Do NOT restart clonidine at a lower dose thinking you are being cautious – the patient was already on 0.1 mg TID, and underdosing increases withdrawal risk. 3, 4
• Do NOT discharge without confirming the patient has the CORRECT medication in hand and understands the dosing schedule. 7, 8, 9
• Do NOT overlook that clonidine was prescribed PRN – clarify with the prescriber whether this should be scheduled or truly as-needed, as PRN dosing increases the risk of inadvertent withdrawal. 3, 4