Medical Weight Loss with GLP-1 Therapy

Obesity worsens a striking share of what we treat — urinary incontinence, kidney stones, erectile dysfunction, low testosterone, BPH progression, and several cancers — so helping patients lose weight is both good medicine and a natural growth opportunity for the practice. GLP-1–based therapy, led by semaglutide, has made durable medical weight loss realistic for the first time. This chapter covers eligibility, the titration schedule, monitoring, and the safety points that matter.

24.1 Why this belongs in a urology practice

• The urologic payoff is direct: weight loss improves stress and urgency incontinence (a 5–10% loss produces measurable improvement), lowers stone-forming risk, raises endogenous testosterone (adipose tissue aromatizes testosterone to estradiol — losing fat raises T without a prescription), improves erectile function, and reduces the progression of BPH and the risk of several cancers.

• Many of our patients already carry the qualifying comorbidities (hypertension, type 2 diabetes, sleep apnea) and see us regularly — we are well positioned to help, and often better positioned than anyone else in their care.

• How GLP-1 agonists work: they mimic an endogenous incretin — enhancing glucose-dependent insulin secretion, suppressing glucagon, SLOWING GASTRIC EMPTYING, and acting centrally on hypothalamic appetite centers to reduce hunger and food noise. The gastric-emptying effect explains both the satiety and most of the side effects.

24.2 Who qualifies

• BMI ≥ 30, or BMI ≥ 27 with a weight-related comorbidity (hypertension, type 2 diabetes, dyslipidemia, obstructive sleep apnea, cardiovascular disease). Document the qualifying BMI and comorbidity explicitly — coverage depends on it.

• Combine the medication with a foundation of nutrition (adequate protein — 1.2–1.5 g/kg to protect lean mass), resistance exercise, sleep, and behavioral support. The drug is an adjunct, not a substitute, and patients who neglect protein and resistance training lose a substantial fraction of their weight as muscle.

24.3 Semaglutide (Wegovy) — titration schedule

Semaglutide is a once-weekly subcutaneous GLP-1 receptor agonist. The dose is escalated slowly to minimize gastrointestinal side effects. Escalate only if the current dose is tolerated — it is fine to hold a step longer, and the lowest dose that maintains results is the right dose.

Tirzepatide (a dual GIP/GLP-1 agonist) is an alternative with its own titration schedule and, in head-to-head data, greater average weight loss; the principles below apply to both classes.

24.4 Monitoring

• Efficacy: track weight and BMI. Expect meaningful loss by 3–6 months at maintenance (roughly 15% average total body weight with semaglutide 2.4 mg in trials). If a patient has lost < ~5% at a full maintenance dose, reassess adherence, injection technique, and the plan — and consider switching agents.

• Tolerance: assess GI symptoms at each step; slow the titration for significant nausea or vomiting rather than abandoning therapy.

• Glucose (if diabetic): reduce insulin and sulfonylureas proactively to avoid hypoglycemia; monitor glucose. GLP-1 agonists alone rarely cause hypoglycemia.

• Hydration and kidneys: dehydration from vomiting/diarrhea can precipitate acute kidney injury — counsel on fluids. This is doubly important for our stone formers, in whom dehydration is the enemy.

• Other: watch for gallbladder symptoms (rapid weight loss promotes gallstones); in diabetics with retinopathy, rapid glucose lowering can transiently worsen it; screen mood; and monitor for muscle loss (encourage protein and resistance training).

24.5 Side effects, warnings, and contraindications

• Common (mostly GI, mostly dose-related, mostly transient): nausea, vomiting, diarrhea, constipation, abdominal discomfort, eructation, and fatigue — they improve with slow titration and smaller, lower-fat meals.

• Serious (uncommon): pancreatitis (stop the drug for severe persistent abdominal pain radiating to the back), gallstones/cholecystitis, and delayed gastric emptying progressing to gastroparesis or ileus.

• Boxed warning: thyroid C-cell tumors in rodents — CONTRAINDICATED with a personal or family history of medullary thyroid carcinoma or MEN 2 syndrome. Ask about this before every prescription.

• Pregnancy: discontinue before a planned pregnancy (at least 2 months prior for semaglutide) and do not use during pregnancy.

• Set expectations honestly: weight regain is common after stopping. These are chronic-disease medications, like antihypertensives — not a short course. Discuss the long-term plan up front so the patient is not blindsided.

24.6 The APP's role

• Screen for eligibility and document the qualifying BMI/comorbidity for coverage; set expectations and build the behavioral plan.

• Initiate and titrate per the schedule, manage GI side effects, and monitor as above.

• Coordinate with primary care and endocrinology for diabetics and complex patients, and reassess response at 3–6 months.

• Always ask about GLP-1 use in your PRE-OPERATIVE patients — even if we did not prescribe it. Many patients get these drugs elsewhere (including from telehealth and compounded sources) and will not volunteer it.