Phentermine: A Systematic Review for Plastic and Reconstructive Surgeons.

Area of Science:

• Anesthesiology
• Pharmacology
• Plastic Surgery

Background:

• Phentermine is a widely prescribed antiobesity medication.
• Case reports indicate potential anesthetic risks, including refractory hypotension, during perioperative use.
• Lack of published guidelines for managing phentermine in plastic surgery patients necessitates safety recommendations.

Purpose of the Study:

• To conduct a systematic review of phentermine's pharmacology and associated anesthetic risks.
• To provide evidence-based management recommendations for perioperative phentermine use in plastic surgery.

Main Methods:

• Systematic review of PubMed/MEDLINE, EMBASE, and Scopus databases.
• Focused on phentermine pharmacology and perioperative anesthetic complications.
• Analyzed 251 citations, identifying 4 relevant articles (1 review, 2 case reports, 1 letter).

Main Results:

• Identified perioperative phentermine use complications including hypotension, hypertension, hypoglycemia, hyperthermia, bradycardia, cardiac depression, and pulmonary edema.
• Hypotension upon general anesthesia induction was the most frequently reported complication.
• Phentermine-induced hypotension may not respond to catecholamine-dependent vasopressors like ephedrine.

Conclusions:

• The precise relationship between phentermine and anesthesia remains unclear.
• Caution is advised for elective surgery in patients taking phentermine due to potential anesthetic complications.
• Recommend discontinuing phentermine at least 4 days prior to surgery, with patient awareness of risks and vigilant intraoperative monitoring by an anesthesiologist.