Side effects across medicines

Medicines whose labels list constipation

808 medicines have an FDA label that names constipation in its boxed warning, warnings, adverse reactions, trial table, patient leaflet or Drug Facts “stop use” warning (of the labels PlainMeds reads: each medicine's quoted label and up to eight more, by route and wording). Among them, the most FAERS reports of constipation name lenalidomide (11,085), ergocalciferol (10,265) and omeprazole (9,541), through July 30, 2026. A label lists what its studies and reports found, and a report does not show that a medicine caused the event.

Check it at the source: the FDA FAERS public dashboard; FDA labels on DailyMed.

Which medicines' labels list constipation?

Ordered by where the label names it, the boxed warning first, then by FAERS reports. The first 150 of the 808 are below; every other one is on its medicine record. A medicine whose own indications name it, because it treats it, is not counted.

Medicine	Where a label names it	FAERS reports of constipation
Carbidopa and levodopa	warnings and precautions (enteral label)	1,374
Acetaminophen and hydrocodone	precautions	981
Buprenorphine	precautions (intramuscular/intravenous label)	957
Prochlorperazine	precautions	948
Methadone	precautions (intramuscular/intravenous/subcutaneous label)	830
Oxybutynin	warnings (transdermal label)	751
Acetaminophen and oxycodone	precautions	445
Cholestyramine	precautions	409
Granisetron	warnings and precautions (subcutaneous label)	401
Acetaminophen and codeine	precautions	337
Glycopyrrolate	warnings and precautions (oral label)	122
Aspirin and oxycodone	precautions	none in the top 1,000
Butorphanol	precautions	none in the top 1,000
Colestipol	precautions	none in the top 1,000
Doxercalciferol	warnings and precautions (oral label)	none in the top 1,000
Hydrocodone and ibuprofen	precautions	none in the top 1,000
Levorphanol	precautions	none in the top 1,000
Nalbuphine	precautions	none in the top 1,000
Paricalcitol	warnings and precautions (intravenous label)	none in the top 1,000
Vinblastine	precautions	none in the top 1,000
Lenalidomide	adverse reactions	11,085
Ergocalciferol	adverse reactions	10,265
Omeprazole	adverse reactions	9,541
Gabapentin	adverse reactions	8,105
Furosemide	adverse reactions	8,064
Tirzepatide	adverse reactions	6,502
Pantoprazole	adverse reactions	5,928
Lisinopril	adverse reactions	5,759
Amlodipine	adverse reactions	5,496
Pregabalin	adverse reactions	5,261
Metoprolol	adverse reactions	5,145
Simvastatin	adverse reactions	4,946
Ondansetron	adverse reactions	4,761
Semaglutide	adverse reactions	4,724
Alprazolam	adverse reactions	4,493
Lorazepam	adverse reactions	4,381
Oxycodone	adverse reactions	4,231
Niraparib	adverse reactions	4,105
Losartan	adverse reactions	3,836
Esomeprazole	adverse reactions (intravenous label)	3,612
Clonazepam	adverse reactions	3,472
Diphenhydramine	adverse reactions	3,453
Quetiapine	adverse reactions	3,363
Erenumab	adverse reactions	3,184
Hydrochlorothiazide	adverse reactions	3,099
Morphine	adverse reactions	3,098
Citalopram	adverse reactions	2,902
Palbociclib	adverse reactions	2,790
Zolpidem	adverse reactions	2,770
Pomalidomide	adverse reactions	2,668
Venlafaxine	adverse reactions	2,643
Sevelamer	adverse reactions	2,547
Teriparatide	adverse reactions	2,544
Diazepam	adverse reactions	2,513
Escitalopram	adverse reactions	2,509
Alendronate	adverse reactions	2,483
Clozapine	adverse reactions	2,399
Tiotropium	adverse reactions	2,394
Rosuvastatin	adverse reactions	2,390
Cabozantinib	adverse reactions	2,377
Bevacizumab	adverse reactions	2,346
Dulaglutide	adverse reactions	2,342
Denosumab	adverse reactions	2,274
Bupropion	adverse reactions	2,246
Varenicline	adverse reactions	2,219
Bortezomib	adverse reactions	2,201
Cyclobenzaprine	adverse reactions	2,165
Hydromorphone	adverse reactions	2,154
Carboplatin	adverse reactions	2,152
Patiromer	adverse reactions	2,143
Fentanyl	adverse reactions (transdermal label)	1,972
Sertraline	adverse reactions	1,968
Olanzapine	adverse reactions	1,964
Celecoxib	adverse reactions	1,963
Infliximab	adverse reactions	1,943
Mirtazapine	adverse reactions	1,906
Capecitabine	adverse reactions	1,891
Diclofenac	adverse reactions (oral label)	1,857
Fluoxetine	adverse reactions	1,853
Bisoprolol	adverse reactions	1,846
Enzalutamide	adverse reactions	1,823
Ciprofloxacin	adverse reactions (intravenous label)	1,792
Baclofen	adverse reactions	1,783
Ramipril	adverse reactions	1,744
Cyclophosphamide	adverse reactions	1,729
Letrozole	adverse reactions	1,693
Duloxetine	adverse reactions	1,617
Ranitidine	adverse reactions	1,598
Liraglutide	adverse reactions	1,593
Risperidone	adverse reactions	1,593
Aripiprazole	adverse reactions	1,527
Sitagliptin	adverse reactions	1,496
Metronidazole	adverse reactions	1,447
Pembrolizumab	adverse reactions	1,432
Dalfampridine	adverse reactions	1,415
Pimavanserin	adverse reactions	1,397
Nivolumab	adverse reactions	1,388
Carbamazepine	adverse reactions	1,384
Glipizide	adverse reactions	1,384
Clonidine	adverse reactions	1,370
Lamotrigine	adverse reactions	1,343
Mirabegron	adverse reactions	1,338
Topiramate	adverse reactions	1,310
Levofloxacin	adverse reactions	1,287
Estradiol	adverse reactions (transdermal label)	1,268
Levetiracetam	adverse reactions	1,242
Mesalamine	adverse reactions (rectal label)	1,238
Empagliflozin	adverse reactions	1,195
Trastuzumab	adverse reactions	1,192
Exenatide	adverse reactions	1,177
Ruxolitinib	adverse reactions	1,154
Diltiazem	adverse reactions	1,150
Propranolol	adverse reactions	1,137
Ribociclib	adverse reactions	1,135
Octreotide	adverse reactions	1,113
Budesonide	adverse reactions (oral label)	1,088
Ibrutinib	adverse reactions	1,058
Pancrelipase amylase and pancrelipase lipase and pancrelipase protease	adverse reactions	1,026
Relugolix	adverse reactions	1,015
Azithromycin	adverse reactions	1,013
Sunitinib	adverse reactions	1,012
Thalidomide	adverse reactions	996
Ipratropium	adverse reactions	994
Ixazomib	adverse reactions	967
Riociguat	adverse reactions	950
Fulvestrant	adverse reactions	924
Natalizumab	adverse reactions	920
Oxaliplatin	adverse reactions	908
Lenvatinib	adverse reactions	904
Sucralfate	adverse reactions	896
Anastrozole	adverse reactions	873
Venetoclax	adverse reactions	865
Docetaxel	adverse reactions	841
Everolimus	adverse reactions	841
Cyclosporine	adverse reactions	802
Nifedipine	adverse reactions	798
Zoledronic acid	adverse reactions	790
Amitriptyline	adverse reactions	789
Dexlansoprazole	adverse reactions	788
Rucaparib camsylate	adverse reactions	785
Gemcitabine	adverse reactions	763
Progesterone	adverse reactions	758
Calcitriol	adverse reactions	738
Enalapril	adverse reactions	738
Leuprolide	adverse reactions	723
Etoposide	adverse reactions	719
Quinapril	adverse reactions	713
Tramadol	adverse reactions	704
Fenofibrate	adverse reactions	700
Dapagliflozin	adverse reactions	693

Source: FDA drug labels via openFDA, read October 8, 2026; FAERS via openFDA, reports through July 30, 2026

Which of them have the most constipation reports in FAERS?

Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is.

Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; MedDRA preferred term “Constipation”

What next?

Side effects across medicines: every reaction on PlainMeds
Report a side effect to the FDA: MedWatch