Tegaserod

ZELNORM

What it is5-HT4 partial agonist; IBS with constipation in women under 65.

Why this oneIt accelerates transit and relieves pain in constipation-predominant IBS.

What limits itWithdrawn in 2007 for ischemic cardiovascular events, then reintroduced with restriction to low-risk women.

FDA-approved for

FDA dosing	Population	Start	Target	Max
IBS with constipation (IBS-C)	Women <65 yr	6 mg BID	6 mg BID	6 mg BID

Renal Contraindicated if severe (eGFR <15) or ESRD; no adjustment for mild-moderate (eGFR ≥30)

Hepatic Contraindicated if moderate-severe (Child-Pugh B or C); no adjustment for mild

History of MI, stroke, TIA, or angina
History of ischemic colitis or other intestinal ischemia
Severe renal impairment (eGFR <15) or ESRD
Moderate/severe hepatic impairment (Child-Pugh B or C)
History of bowel obstruction, symptomatic gallbladder disease, suspected sphincter of Oddi dysfunction, or abdominal adhesions

Cardiovascular ischemic events including MACE — assess CV history/risk before use; discontinue if MI/stroke/TIA/angina
Ischemic colitis — discontinue if rectal bleeding, bloody diarrhea, or new/worsening abdominal pain; do not reinitiate
Volume depletion from diarrhea (hypovolemia, hypotension, syncope) — avoid in patients with diarrhea
Suicidal ideation and behavior — monitor for worsening depression

Pregnancy Available data have not identified a drug-associated risk of major birth defects or miscarriage

Lactation Breastfeeding not recommended during treatment (present in rat milk; tumorigenicity concern)

NO BOXED WARNINGS

Principal riskWithdrawn in 2007 for ischemic cardiovascular events, then reintroduced with restriction to low

Direct muscarinic antagonism0 / 4