Presentation is loading. Please wait.

Presentation is loading. Please wait.

Medication related changes in the post-bariatric surgery population Christopher Giuliano, Pharm.D. Assistant Professor, Internal Medicine Clinical Specialist.

Similar presentations


Presentation on theme: "Medication related changes in the post-bariatric surgery population Christopher Giuliano, Pharm.D. Assistant Professor, Internal Medicine Clinical Specialist."— Presentation transcript:

1 Medication related changes in the post-bariatric surgery population Christopher Giuliano, Pharm.D. Assistant Professor, Internal Medicine Clinical Specialist

2 Medication absorption after gastric surgery could A.Increase B.Decrease C.Not change D.B or C E.All of the above

3 Objectives  Distinguish the differences between restrictive and restrictive-malabsorptive bariatric surgeries  Identify medication related changes in patients after bariatric surgery  Create a medication regimen based off suspected pharmacokinetic changes in a patient case  Identify nutritional deficiencies associated with bariatric surgery

4 Case  FC is a 45 yof that presents with a chief complaint of feeling dizzy. She has a PMH of DM, HTN, HLD, atrial fibrillation, roux-en-y gastric bypass (RYGB) surgery (4 months prior), and major depression.  Vitals temp 98.6°, HR 115, BP 102/70,RR 20  Physical Exam: Tachycardic, irregularly irregular pulse, all else WNL

5 Case  EKG- Afib  Labs (In ER in am)  Na 135, K 4.3, CL 101, CO2 26, Cr 1.0, BUN 13, Ca 8.6, Glucose 65  Hgb 9, Hct 33, MCV 55, WBC 7, Platelets 325  Iron 20, Ferritin 10, B12 600, folate 15  LDL 40

6 Case  Medications (been on for “years”)  Insulin glargine 30 units qhs  Insulin aspart 10 units with meals  Diltiazem XR 360 mg daily  Hydrochlorothiazide 25 mg daily  Lisinopril 20 mg daily  Atorvastatin 80 mg qhs  Sertraline 20 mg qhs  Multivitamin qd, B12 1 mg PO daily, Ca/VitD 500/400 BID

7 Normal anatomy Accessed 12/1/14

8 Restrictive procedures  Vertical Banded Gastroplasty  Adjustable Gastric Banding  Sleeve Gastrectomy Miller A, et al. AJHP. 2006;63:1852-7

9 Malabsorptive procedures  Jejunoileal bypass Miller A, et al. AJHP. 2006;63:1852-7

10 Restrictive-malabsorptive  Roux-en-y*L  Biliopancreatic diversion Miller A, et al. AJHP. 2006;63:1852-7

11 Giuliano et al. Adv Pharmacoepidem Drug Safety. 2012; S1-6 Gastric mixing, volume, ph, residence time No duodenal absorption! What if my active transporter is in the duodenum? PgP increases significantly in jejunum and ileum Remember the grapefruit juice interaction with intestinal CYP3A4? What if the drug undergoes enterohepatic recirculation?

12 Drug disintegration and dissolution  Disintegration  Gastric mixing  Clinical pearl- give liquid formulation  Dissolution and solubility  Gastric ph  Clinical pearl- avoid extended release products, if PPI interacts be careful  Gastric emptying

13 Which medication could be switched to another dosage form? A.Sertraline B.Atorvastatin C.Diltiazem XR D.Lisinopril

14 Drug disintegration and dissolution  The role of bile acids  Lipophilicity  Tacrolimus  Enterohepatic recirculation  Cyclosporine, rifampin, phenytoin, levothyroxine, oral contraceptives Accessed 12/1/14

15 Mucosal exposure  Length of bypassed segment  Transit time  Intestinal adaptation Miller A, et al. AJHP. 2006;63:1852-7

16 Absorption across intestines  Metabolism (CYP3A4)  Active transport (OAT)  Efflux (P-glycoprotein)  E.g. cyclosporine

17 The evidence: jejunoileal bypass Decreased Absorption  Phenytoin (9)  Ethosuximide (1)  Rifampin (6)  Ethambutol (2)  Cyclosporine (2)  Tacrolimus (1)  Levothyroxine (2)  Ampicillin (6)  HCTZ (4)  Digoxin (9) No Change  Isoniazid (9)  Ethambutol (7)  Phenazone (17)  Acetaminophen (3)  Digoxin (7)  Propylthiouracil (3) Padwal R, et al. Obesity Reviews. 2010;11:41-50

18 Gastric surgery: contraceptives  71% of 98 anovulatory women achieved normal menstrual cycles  2 pharmacokinetic studies in JIB patients  Lower levels of NET and LNG  No reduced levels of D-norgesterol or estrogens  2 observational studies  2 out of 9 BPD women using oral contraceptives became pregnant  Of 215 patients, no LAP-band patient on OC became pregnant Teitelman M, et al. Obes Surg. 2006;16:1457–63. Gerrits E, et al. Obes Surg 2003;13:378–82. Weiss HG, et al. Obes Surg 2001;11: 303–6. Victor A, et al. Gastroenterol Clin North Am 1987;16:483–91 Andersen AN, et al. Int J Obes 1982;6:91–6.

19 Nutritional deficiencies RYGBSleeve B1242.1%*5% Iron30%36.4% Folic acid20%18.4% Vitamin D56.3%39.6% Alexandrou E, et al. Surgery for Obesity and Related Diseases. 2014; 10(2):

20 RYGB: iron  67 RYGB women were followed over 18 months  1.5% anemic at baseline compared to 38.8%  7.5% low ferritin at baseline compared to 37.3% Ruz M, et al. Am J Clin Nutr. 2009;90:

21 Other nutritional deficiencies  Thiamine  Copper  Zinc  Vitamin A, D, E, K Saltzman E, et al. Annu Rev Nutr. 2013; 33:

22 What type of anemia does our patient have? A.Iron deficiency B.B12 deficiency C.Folate deficiency D.Anemia of chronic disease

23 RYGB case reports  Magee et al.  29 year old woman with RYGB who failed treatment with amoxicillin and nitrofurantoin, required IV abx  Sobieraj et al.  71 year old women with RYGB and complete gastrectomy who needed larger doses of warfarin  Wills et al.  3 cases of women with RYGB who had subtherapeutic tamoxifen levels Magee SR, et al. J Am Board Fam Med 2007; 20: 310–313 Sobieraj, et al. Pharmacotherapy 2008; 28(12): Adami GF et al. Obes Surg 1991; 1: 293–294

24 RYGB case reports  Fuller et al.  51 year old female with RYGB who required transient increase in haloperidol dosage  Tripp et al  1 Case of lithium toxicity after RYGB in patient on for 10 years Fuller AK, et al. J Clin Psychopharmacol. 1986; 6: 376–377 Wills, SM, et al. Pharmacotherapy. 2010; 30(2):217 Tripp, AC. Journal of Clinical Physcopharmacology. 2011;31(2):261-2

25 RYGB case reports  Michelak et al.  27 year old female with RYGB with lower levels of HIV medications (lamivudine, zidovudine, lopinavir, ritonavir)  Knoll BM  Isavuconazole in patient with RYGB required twice normal dose to achieve therapeutic levels Michelak DE, et al. J Int Ass of AIDS care. 2014; 1: 1-4 Knowll EM. Journal of Antimicrobial Chemotherapy. 2013;

26 RYGB: Alcohol  5 RYGB patients (no control)  Cmax  After 2 minutes over driving limit of 0.08%  Cmax was 0.138%  Tmax  5.4 minutes Steffen KJ, et al. Surgery for Obesity and Related Diseases. 2013; 9: 470-3

27

28 RYGB: Sertraline  5 matched RYGB patients  Excluded  Ultra-rapid and poor metabolizers  Drug interactions  AUC  RYGB vs. control (124 vs. 314, p 0.043)  Range ( vs ) Roerig JL, et al. Surgery for Obesity and Related Diseases. [Epub ahead of print on 12/15/2014]

29 RYGB: Duloxetine  10 matched RYGB patients  Excluded  Ultra-rapid and poor metabolizers  Drug interactions  AUC 0-∞  RYGB vs. control (646.7 vs , p 0.017)  Range ( vs ) Roerig JL, et al. Journal of Clinical Psychopharmacology. 2013; 3:

30 RYGB: Azithromycin  14 matched RYGB patients  AUC 0-24  RYGB vs. control (1.41 vs. 2.07, p 0.008)  Peak  RYGB vs. control (0.26 vs. 0.36, p 0.08) Padwal R, et al. Journal of Antimicrobial Chemotherapy. 2012;67:2203-6

31 RYGB: Linezolid  4 patients before and 3 months after RYGB  AUC 0-∞  After vs. before (98.9 vs. 41.6, p <0.05)  No change in bioavailability  Peak  After vs. before (7.3 vs. 9.2) Hamilton R, et al. Journal of Antimicrobial Chemotherapy. 2013;68:666-73

32 RYGB: Moxifloxacin  12 RYGB patients (crossover between IV and oral)  No change in bioavailability  AUC and peak 50% higher than reference De Smet J, et al. Journal of Antimicrobial Chemotherapy. 2012;67:226-9

33 RYGB: Atorvastatin  12 patients 5 weeks post RYGB  8 patients had increased atorvastatin levels  3 patients with highest levels pre-surgery had 2.6 fold decrease in levels  Why? Skottheim IB, et al. Clinical Pharmacology and Therapeutics. 2009;86(3):

34 You should consider making what change to the atorvastatin dose? A.Increase B.Decrease C.Discontinue D.No change

35 RYGB: Metformin  16 patients post RYGB versus match controls  AUC 0-∞ was calculated  AUC 0-∞ was increased by 21%  Bioavailability increased by 50%  A difference was seen in AUC glucose of 5.9ug/ml/hr over 8 hours Padwal RS, et al. Diabetes Care. [Epub ahead of print on 04/08/2011]

36 RYGB: Pain medication  Morphine solution  30 patients before and 6 months after RYGB  AUC 0-24  After vs. before (54.7 vs. 44.8, p <0.05)  Peak  After vs. before (38.1 vs. 11.3, p<0.05)  Oxycodone  Total gastrectomy  No change in AUC; although compared to reference Szalek R, et al. European Review for Medical and Pharmacological Sciences. 2014;18:

37 RYGB: Immunosuppresants  6 gastric bypass patients with ESRD  Tacrolimus AUC 0-∞ decreased 20%  Sirolimus AUC 0-∞ decreased 37%  MMF AUC 0-∞ decreased 38% Rogers CC, et al. Clin Transplant. 2008; 22: 281–291

38 Other medication changes  Decreased need for medications for:  Hypertension  Diabetes  Hyperlipidemia  One study conducted in 298 VA patients found  52% of patients discontinued DM medications  40% discontinued HLD medications Maciejewski ML, et al. Surgery for Obesity and Related Diseases. 2010;6:601-07

39 Our patients blood pressure and diabetes medications may need to be A.Decreased B.Increased C.No change

40 General rules  If efficacy or safety is a major concern  Choose something that you can monitor  Drugs most likely to display absorption issues  Low bioavailability, high lipophilicity, and enterohepatic circulation  Avoid ER, EC, DR products if possible  Administer medication via a different route  Monitor patients clinically

41 Questions?

42 The most commonly used restrictive- malabsorptive bariatric surgery procedure is A.Roux-en-Y gastric bypass B.Vertical banded gastroplasty C.Adjustable gastric banding D.Biliopancreatic diversion

43 Post bariatric surgery patients have shown decreased need for A.Antidepressants B.Gastric suppressant agents C.Diabetes medications D.Contraceptives

44 A post RYGB patient is likely to experience decreased medication absorption if the medication has/is A.Low bioavailability B.High lipophilicity C.Extended release D.All of the above

45 Common nutritional deficiencies in patients undergoing gastric bypass surgery include A.Vitamin B12 B.Iron C.Folate D.Vitamin A,D, E, K E.All of the above


Download ppt "Medication related changes in the post-bariatric surgery population Christopher Giuliano, Pharm.D. Assistant Professor, Internal Medicine Clinical Specialist."

Similar presentations


Ads by Google