13. Appendix 4 - drug interactions

Question 1

Name 5 drugs that Warfarin interacts with?

Answer 1

1. NSAIDs
2. Carbamazepine
3. Azole antifungals
4. Metronidazole Abx
5. Macrolide Abx

Question 2

What can occur in someone taking statins who is prescribed azoles and clarithomycin?

Answer 2

Myopathy

Question 3

What drug can exacerbate asthma symptoms?

Answer 3

NSAIDs

Question 4

What 2 common drugs interact with metronidazole?

Answer 4

1. Alcohol
   –> advise pts to avoid alcohol
2. Warfarin
   –> do not prescribe metronidazole for pts taking warfarin

Question 5

What common drugs do macrolide antibiotics interact with? (e.g. clarithromycin)

Answer 5

1. Calcium channel blockers (e.g. nifedipine)
2. Carbamazepine
3. Ciclosporin
4. Domperidone
5. Statins (e.g. simvastatin)
6. Theophylline
7. Warfarin

–> DO NOT PRESCRIBE MACROLIDE ANTIBIOTICS FOR PATIENTS TAKING THESE DRUGS

Question 6

What common drugs interact with Azole antifungals? (e.g. fluconazole, miconazole) (3)

Answer 6

1. Statins
2. Warfarin
3. Theophylline

–> DO NOT PRESCRIBE AZOLE ANTIFUNGALS FOR PATIENTS TAKING THESE DRUGS

Question 7

What common drugs interact with NSAIDs (e.g. ibuprofen, diclofenac)? (7)

Answer 7

1. Antihypertensives drugs esp. beta-blockers (e.g. atenolol), ACE inhibitors (e.g. lisinopril) and diuretics.
   –> Avoid prescribing NSAIDs or ensure course is for 5 days or less.
2. Anticoagulants (e.g. warfarin, dabigatran)
   –> DO NOT PRESCRIBE NSAIDS
3. Aspirin
   –> DO NOT PRESCRIBE NSAIDS FOR PTS TAKING A DAILY LOW DOSE OF ASPIRIN
4. Lithium
   –> Do not prescribe NSAIDs
5. Methotrexate
   –> Avoid prescribing NSAIDs
6. Selective serotonin reuptake inhibitors (SSRIs e.g. fluoxetine)
   –> Avoid prescribing NSAIDs
7. Systemic corticosteroids
   –> Only prescribe NSAIDs in combination with a proton-pump inhibitor.

Question 8

Which common drugs interact with aspirin? (6)

Answer 8

1. Alcohol
   –> Advise pt to avoid alcohol for 12 hours after taking aspirin
2. Clopidogrel
   –> Avoid prescribing aspirin
3. NSAIDs (e.g. ibuprofen, diclofenac)
   –> Do not prescribe aspirin
4. Selective serotonin reuptake inhibitors (SSRIs e.g. fluoxetine)
   –> Avoid prescribing aspirin
5. Systemic corticosteroids
   –> Only prescribe aspirin in combination with a proton-pump inhibitor
6. Warfarin
   –> Do not prescribe aspirin for pts taking warfarin