Table 2.

Medication management strategies for specific chronic disease states after bariatric surgery: Based on the anticipated medication and absorption changes after 3 specific procedures: 2 types of restrictive procedures (gastric banding and sleeve gastrectomy) and 1 type with both restrictive and malabsorptive properties (RYGB).

DISEASE STATE OR MEDICATION CLASS	COMMENTS
Diabetes	Frequent follow-up and monitoring by a health care provider is required in the postoperative period to ensure ongoing effectiveness and timely modifications of antihyperglycemic medications⁷ While the medication burden might decrease initially after surgery, long-term monitoring is recommended given that diabetes is a progressive disease and can worsen with time in some patients⁷ Drug-specific recommendations for type 2 diabetes Insulin^* Insulin requirements might be volatile and are expected to decrease for at least 12 months after surgery or until weight loss stabilizes, with the most substantial reductions occurring during the first months^7,8 If the basal insulin dose is < 30 units/day before surgery, then discontinue after surgery^7–9 If the basal insulin dose is ≥ 30 units/day before surgery, then decrease by 50% to 80% after surgery^7–10 Short-acting insulin might be used to manage elevated glucose levels^7–9 Noninsulin options In patients taking 1 oral antidiabetic agent before surgery, the agent can be discontinued after surgery^8,9 If the patient is taking > 1 oral medication and ... -HbA_1c is < 9%, metformin is the preferred single-agent therapy^7,10 -HbA_1c is ≥ 9%, a second agent can be coupled with metformin, preferably an agent that facilitates CV risk reduction^{7,11^†} Avoid oral medications that increase the risk of hypoglycemia^{7,8,11^‡}
Anticoagulation	Warfarin is preferred over DOACs in patients who require continuous anticoagulation after bariatric surgery¹² -If considering DOAC therapy after bariatric surgery, then confirm that drug-specific laboratory monitoring is available to ensure levels are within the expected therapeutic range¹² Drug-specific recommendations Warfarin Warfarin doses should typically decrease in the immediate postoperative period (about 3–4 wk) and then increase further out from surgery^12–14 To reduce bleeding risk, decrease the warfarin dose after surgery and adjust it based on the INR results, similar to a new warfarin start Apixaban, rivaroxaban Limited evidence suggests that rivaroxaban and apixaban do not require dose adjustment after bariatric surgery^15,16 Drug-specific laboratory monitoring is recommended to ensure levels are within the expected therapeutic range¹² Dabigatran, edoxaban Literature outlining the pharmacokinetic changes to dabigatran and edoxaban after bariatric surgery is lacking¹²
Antiplatelet therapy	Antiplatelet therapy might increase the risk of gastrointestinal bleeding^5,6 -Antiplatelet medication for primary prevention of CV events should be reassessed -Continuing antiplatelet therapy in patients who are at high risk of future CV events is appropriate at the lowest indicated dosage
Dyslipidemia	Lipid levels might decrease with weight loss; consider monitoring every 3 mo until weight loss stabilizes and discontinue therapy if appropriate^17–19 In patients who are taking dyslipidemia therapy for secondary prevention of CV events, the dose might be determined by the previous event rather than postoperative laboratory values
Hypertension	The need to use antihypertensive medications typically decreases after surgery. This decrease might begin immediately after surgery and continue for up to 2 y^20–22 -Patients should have frequent follow-up with a general practitioner -Patients should monitor their blood pressure daily until it stabilizes —Results should be recorded and assessed by a health care professional to support medication changes —Patients should be reminded of the correct self-monitoring technique Consider discontinuing or changing diuretic therapy if patients develop dehydration⁸ In patients with diabetes it might be preferable to continue an ACEI or ARB owing to their renoprotective effects⁸
Depression and anxiety	Close monitoring for psychiatric symptom relapse after surgery is recommended²³ -Patients should be aware of the signs and symptoms of worsening psychiatric illness and be advised of whom to contact if this occurs If relapse occurs, adjust psychiatric medications as quickly as possible owing to the anticipated lengthy response time associated with changing regimens The literature suggests that the concentration of SSRIs might drop initially and then rebound within a few months; dose adjustments occurring in the immediate postoperative period might be temporary^23,24 Switching to a formulation that is absorbed more readily (eg, liquids, crushed pills, immediate-release preparations, tablets that dissolve orally) might be necessary Drug-specific recommendations for medications that do not have an immediate-release version available in Canada Venlafaxine The literature suggests that RYGB does not substantially alter the absorption of extended-release venlafaxine or its active metabolite²⁵ Duloxetine RYGB might decrease patients’ exposure to duloxetine and this might persist for at least 12 mo after surgery²⁶ -If therapy appears to be ineffective after surgery, then an increased dose or alternative therapy might be required Desvenlafaxine If therapy appears to be ineffective after surgery, then an increased dose or alternative therapy might be required Bupropion If therapy appears to be ineffective after surgery, consider the following: -Continuing or changing to SR bupropion —SR formulation is easier to crush than the extended-release formulation -Crush tablets and administer with water; this is expected to provide effects similar to the immediate-release tablets available outside of Canada -Divide total daily dosage in 3 to 4 daily doses. Maximum single dose should not exceed 150 mg, and maximum total daily dose should not exceed 450 mg²⁷
Migraine	Migraine or headache frequency might decrease after surgery^28,29 Average time to medication reduction was about 5.6 mo after surgery (range 1 to 36 mo)²⁸ If initial migraines began after obesity onset, there is a greater probability that migraines will resolve postoperatively²⁸
Epilepsy or seizures	Seizures should be well controlled with medications before surgery Consider empirically switching to a liquid formulation, crushable tablets, or capsules that can be opened before malabsorptive procedures Where indicated, drug monitoring during the early postoperative period is recommended to ensure therapeutic drug levels
Asthma	Patients with asthma might require less medication after surgery^30,31 -If patients report decreased rescue medication use, then consider reducing or discontinuing maintenance therapy
Psoriasis	Patients with psoriasis might require less medication after surgery^32,33 -If patients report decreased psoriasis severity, consider reducing or discontinuing therapy
Pain	Avoid NSAIDs after bariatric surgery owing to increased risk of gastric injury (eg, marginal ulcers)^4,6 For patients undergoing malabsorptive surgery and who are taking extended-release medications or high-dose opioid therapy, consider changing to immediate-release formulations or alternate routes of administration before surgery Liquid acetaminophen contains sorbitol, which increases the risk of dumping syndrome⁶
Transplant	If the patient is receiving transplant medications, consider stabilizing medication levels using a liquid formulation before surgery Increased levels of tacrolimus and mycophenolate have been observed after sleeve gastrectomy³⁴ Where indicated, monitor drug levels postoperatively and adjust the dose as appropriate
Ulcer prevention and GERD	Rapid-dissolve tablets or capsules that can be opened and sprinkled on food might have greater absorption and efficacy for patients after bariatric surgery -Patients who experienced postoperative ulceration healed significantly faster (P < .001) while taking opened and dispersed proton pump inhibitor capsules compared with those taking whole capsules or tablets³⁵ -Prescriber should specify “no substitution” when prescribing dispersible or open capsules
HIV	Sleeve gastrectomy does not appear to negatively affect CD4 counts and viral load, and appears to be safe in individuals living with HIV^36,37 Substantially decreased absorption has been observed with raltegravir and atazanavir after sleeve gastrectomy^36–38 -Suggest replacing raltegravir and atazanavir with alternative HIV therapy before bariatric surgery³⁶ -If replacing raltegravir and atazanavir is not possible, then ensure postoperative pharmacokinetic monitoring is performed and adjust medication doses accordingly³⁶
Contraception	Rocha et al³⁹ and Curtis et al⁴⁰ indicate that for women who have undergone a ... -malabsorptive procedure, oral contraceptives are not recommended owing to a theoretical risk of decreased drug absorption resulting in reduced contraceptive efficacy³⁹ -restrictive procedure, all contraceptive methods are acceptable^39,40 Caution is recommended in all cases. Ensure the patient understands the potential risks of using oral contraception and that secondary methods (eg, male or female condoms, diaphragms) should be employed Drug-specific considerations Effective after restrictive procedures only Combined oral contraceptive Progestin-only pill Effective after both procedures, but might be less effective in women weighing ≥ 90 kg (≥ 198 lb)⁴¹ Ethinyl estradiol and norelgestromin patch Effective after both procedures, but effectiveness in women who are obese is not well studied⁴² Ethinyl estradiol and etonogestrel vaginal ring Effective after both malabsorptive and restrictive procedures Subcutaneous or intramuscular injection of medroxyprogesterone Levonorgestrel intrauterine device Copper intrauterine device

ACEI—angiotensin-converting enzyme inhibitor, ARB—angiotensin II receptor blocker, CV—cardiovascular, DOAC—direct oral anticoagulant, GERD—gastrointestinal reflux disease, HbA_1c—hemoglobin A_1c, INR—international normalized ratio, NSAID—nonsteroidal anti-inflammatory drug, RYGB—Roux-en-Y gastric bypass, SR—sustained release, SSRI—selective serotonin reuptake inhibitor.
↵* Insulin recommendations are based on current published evidence for the treatment of type 2 diabetes mellitus after bariatric surgery. Specific recommendations for type 1 diabetes mellitus were not identified in the current literature, although decreased insulin requirements after surgery have been observed.
↵† Examples of drugs that facilitate CV risk reduction include empagliflozin, canagliflozin, liraglutide, and semaglutide.¹¹
↵‡ Examples of drugs that increase the risk of hypoglycemia include gliclazide, glimepiride, glyburide, and repaglinide.¹¹