Views
1 week ago

2017 HCHB_digital

OTC Medicines:

OTC Medicines: Interactions When selling off-the-shelf medicines, Pharmacy, or Pharmacist Only medicines it is important that the pharmacist checks the product being sold does not interact with any other medicines the customer is already taking. Interactions in this table are generally clinically relevant in the community pharmacy environment. This table is NOT ALL INCLUSIVE, and does not include isolated reports of interactions, theoretical interactions, undocumented interactions, or interactions with uncommonly prescribed medications. When considering a potential interaction, consider the importance of stable blood levels of the concomitant medication, especially for those products with a narrow therapeutic index (eg, warfarin, digoxin). Base product choice on effectiveness and likelihood of interaction. Take into consideration dose and frequency of administration of the pharmacy- sourced medication in determining how clinically relevant the interaction will be (eg, short-term infrequent dosing of a NSAID will usually have clinically irrelevant effects on blood pressure). Always recommend antacids be taken at least two hours apart from other medications, since they can affect the absorption of many drugs. Customers prescribed colestipol and cholestyramine should be reminded these medications can cause reduced or delayed absorption of most medicines and to administer separately, at least one hour before or 4–6 hours after cholestyramine or colestipol. See the New Zealand Formulary (nzf.org.nz) or individual drug datasheets (www.medsafe.govt.nz) for more information. OTC Medicines: Interactions Drug/drug group Interacting substance Details Analgesics – aspirin (moderate-high dose) (Interactions are usually not clinically relevant with low dose aspirin eg, 75–100mg/day) ACE inhibitors and angiotensin II receptor blockers Acetazolamide Increased risk of renal impairment Reduced antihypertensive effect. Low dose aspirin combination acceptable Both acetazolamide and salicylate toxicity possible with high dose aspirin Risk higher in elderly or those with renal impairment Risk of gastric bleeding and ulceration increases as alcohol consumption increases Increased excretion of aspirin in alkaline urine Bleeding time is prolonged and risk of major bleeding episode increased. Avoid combination (only use low dose aspirin only on medical advice) Increased hypoglycaemic effect (excludes metformin). Monitor blood glucose and adjust dosage of oral hypoglycaemics if necessary (unlikely to apply to low dose aspirin) Reduces renal tubular reabsorption of salicylates. May reduce analgesic effects Reduced antihypertensive effect. Low dose aspirin combination acceptable Alcohol Antacids and urinary alkalinisers Anticoagulants (eg, dabigatran, heparin, warfarin) Antidiabetic agents (oral hypoglycaemic agents and insulin) Calcium Calcium channel blockers (eg, amlodipine) Clopidogrel Increased risk of bleeding (low dose aspirin only on medical advice) Corticosteroids Reduced plasma salicylate concentrations resulting in reduced aspirin effect. Increased risk of GI bleed and ulceration Gold compounds Increased risk of hepatotoxicity Loop diuretics (eg, furosemide) Analgesic doses may blunt diuretic and natriuretic response to loop diuretics. Monitor Methotrexate Reduced renal clearance of methotrexate resulting in increased risk of toxicity. Less likely to occur with weekly low dose methotrexate therapy Metoclopramide Increased rate of aspirin absorption and higher peak plasma salicyclate levels. Combination may be beneficial for migraine attacks NSAIDs Additive GI toxicity including increased risk of GI ulceration. Possible prolonged bleeding time. Possible reduction of cardioprotective effect of low dose aspirin Omeprazole, lansoprazole Possibly may decrease absorption of aspirin. May also cause premature dissolution of enteric coated formulations Phenytoin Aspirin may increase pharmacologic and toxic effects of phenytoin. Monitor combination Sodium valproate Increased risk of toxicity. Monitor or avoid high dose aspirin combination SSRI Higher incidence of upper GI bleeding reported (even with low dose aspirin) Uricosurics (eg, benzbromarone, Aspirin, at analgesic doses antagonises the effects of uricosuric drugs. Consider an alternative analgesic/ probenecid) anti-inflammatory. Vaccinations Avoid aspirin use for six weeks after immunisation due to Reye’s syndrome being reported after natural varicella and wild-type influenza infection. Risk is greater in children (avoid aspirin in children

OTC Medicines: Interactions Drug/drug group Interacting substance Details Analgesics – NSAIDs ACE inhibitors and angiotensin II receptor blockers (ARBs) Alcohol Alendronate Anticoagulants (eg, warfarin, heparin) Antidiabetic agents (oral hypoglycaemic agents) Antihypertensives Aspirin (analgesic doses) Aspirin (low dose) Clopidogrel Corticosteroids Increased risk of renal impairment. Elderly people or people with, poor renal perfusion, dehydration, heart failure, or also on diuretics at higher risk. Reduced antihypertensive effect Increased risk of gastric bleeding and ulceration proportional to amount of alcohol consumed Possible increased risk of GI damage (controversial) Bleeding time is prolonged and risk of major bleeding episode increased. Avoid combination Increased hypoglycaemic effect (excludes metformin). Monitor blood glucose and adjust dosage of oral hypoglycaemic agent if necessary Possible reduced hypotensive effect. Monitor BP Additive GI toxicity including increased risk of GI ulceration. Possible prolonged bleeding time. Avoid analgesic/anti-inflammatory doses of aspirin Increased risk of GI bleed. Possible reduction of cardioprotective effect of low dose aspirin Increased risk of bleeding (low dose aspirin only on medical advice) Increased risk of GI bleed and ulceration Cyclosporin Increased risk of nephrotoxicity, increased diclofenac blood levels (reduce diclofenac dose by 50%). Possible increased cyclosporin blood levels with some NSAIDs Digoxin Possible decrease in renal excretion of digoxin resulting in increased digoxin levels with some NSAIDs. Monitor digoxin level Lithium Reduced renal excretion of lithium may result in increased lithium level and toxic effects. Avoid combination unless close monitoring possible Diuretics (eg, furosemide, bendrofluazide) Methotrexate Other NSAIDs Potassium-sparing diuretics and aldosterone antagonists Probenecid Quinolones (eg, ciprofloxacin, norfloxacin) Spironolactone SSRI antidepressants Warfarin Reduced diuretic and antihypertensive effect, possibly due to salt and water retention. Congestive heart failure may be exacerbated. Increased risk of nephrotoxicity, especially with ACE inhibitor or angiotensin II receptor antagonist combination Reduced renal clearance of methotrexate resulting in increased risk of toxicity. Less likely to occur with weekly low dose methotrexate therapy Additive GI toxicity including increased risk of GI ulceration. Increased bleeding time. Avoid Reduced diuretic and antihypertensive effect. Increased risk of nephrotoxicity and hyperkalaemia Increased plasma levels of NSAIDs. Reduce dose of NSAID if using combination Increased risk of CNS stimulation and convulsions. Monitor for CNS adverse effects (eg, seizures, tremors) and avoid combination in patients with epilepsy May reduce diuretic and antihypertensive effect. May increase risk of hyper kalaemia and renal impairment. Risk increased further with ACE inhibitor or ARB, especially if elderly Higher incidence of upper GI bleeding reported See anticoagulants Analgesics – paracetamol Alcohol Risk of severe and sometimes fatal liver damage in people who drink excessively and take even moderate doses of paracetamol. Reduce dose or avoid paracetamol Anticonvulsants (eg, carbamazepine, phenytoin) Metoclopramide Warfarin Efficacy of paracetamol may be reduced due to increased clearance. Increase in toxic metabolites of paracetamol may increase risk of hepatotoxicity. Avoid prolonged use Increased rate of paracetamol absorption. Combination may be beneficial for migraine Possible increased INR with sustained high dose administration of paracetamol. Monitor Antacids Acetazolamide Increased risk of renal calculi if administered with sodium bicarbonate. Avoid regular dosing Digoxin Bioavailability may be decreased. Mechanism unknown. Separate administration by 2–3 hours Enteric coated and delayed release medications H2-antagonists (eg, ranitidine) Early dissolution of formulation may result in dose-dumping in stomach. Separate administration by 2–3 hours Reduced gastric absorption and bioavailability reported. Separate administration Hexamine Sodium bicarbonate alkalinises the urine. Hexamine requires a urinary pH of 5.5 or lower to be active so alkalinisation of urine reduces antibacterial effect. Avoid Iron supplements Some studies show significant reductions in amount of iron absorbed. Separate administration by 2–3 hours Isoniazid Aluminium salts may decrease absorption. Separate administration Lithium Sodium-containing antacids increase lithium excretion (reduce plasma lithium concentrations). Avoid regular dosing Tetracyclines Antacids may decrease plasma tetracycline concentrations by chelation. Separate administration by 2–3 hours Other medications Potential for decreased absorption. Separate administration by 2–3 hours Phenylephrine Sodium bicarbonate alkalinises the urine so renal excretion of phenylephrine may be reduced, increasing risk of side effects (eg, tremors, anxiety, insomnia and/or tachycardia). Monitor for signs of toxicity and adjust dosage as necessary Page 185

19OeNAa
1ziyjlO
national list of essential medicines sri lanka - World Health ...
Knowledge is the best medicine
1zbuVI2
biosimilars_report_en
I - Presentation of the Forum and Current Agenda Areas
Feeling poorly?
Knowledge is the best medicine
Full colour PDF of the pages as they appeared in - Bpac.org.nz
How to deal with military prescriptions - Pharmaceutical Press
seWJe~uelewp~4~Jadue~fie4es UO~S~A~aSa)~AJasle)~lna)ewJe4d
Antimicrobial Packaging Market
Pharmacologic Potpourri: 2012 Update - Healthcare Professionals
o_19a6ftn93haecj01idj7uu1naqa.pdf
CAM2020-FINAL
Get Out! GAY Magazine – Issue 309 – March 29, 2017
Inquiry into Contribution of Community Pharmacy - Association of ...
here - FIP
1420-1440 RevisedEGray_NIBSC_RM_v2 [Read-Only ... - NASCOLA
Pharmacists in sport - Royal Pharmaceutical Society
Objectives OTC/RX/Herbal Background RX/OTC vs ... - sowega ahec
The rapid access dilemma
VMGN 11 - Veterinary Medicines Directorate - Defra
Persisting Pain in Children: Important Information for Pharmacists
PA05-catalogue
Get Out! GAY Magazine – Issue 314 – May 3, 2017
Get Out! GAY Magazine – Issue 333– September 13, 2017
Get Out! GAY Magazine – Issue 347 – December 20, 2017
Get Out! GAY Magazine – Issue 332– September 6, 2017