OTC: Interactions & Extra

Question 1

What drugs can ANTACIDS reduce the absorption of? How would you advice patients

Answer 1

• Tetracyclines
• Quinolones
• Biphosphonates
• Levothroxyine
• E/C meds

Levothyroxine= 4 hour gap
Make sure with all pt leaving gaps

Question 2

Hyoscine: main SE

Answer 2

its an antimuscarinic
so: dry mouth, constipation, dry eyes, tachycardia etc

Question 3

What drugs does IBUPROFEN (NSAID) interact with:

Answer 3

• methotrexate
• lithium
• ciprofloxacin (seizures)
• blood thinners
• SSRIs (blood disorders)
• ACEi (K+)
• Heparin (K+)
• Trimethoprim (K+)

Question 4

What does miconazole interact with?

Answer 4

Warfarin - bleed
carbamazepine - toxicity
ciclosporin, tacrolimus - increases conc
phenytoin - toxicity
sildenafil - increases exposure
simvastatin - avoid, increases exposure

Question 5

What drug does pseudoephedrine interact with causing HYPERTENSIVE crisis (fatal)

Answer 5

MAOIs

so be careful if pt taking linezolid, selegline, rasagline etc.

Question 6

What drugs does sildenafil interact with

Answer 6

any drugs that lower BP
such as:
* nitrates
* antihypertensives

Question 7

What syndrome can St Johns Wort cause

and thus what drugs cant we give with it

Answer 7

Serotonin syndrome
Dont give with SSRIS, ADHD meds, Tramadol

Question 8

Omeprazole is an enzyme inhibitor. However, it actually reduces the conc of one drug

Answer 8

Clopidogrel

Question 9

Omeprazole can cause toxicity of WHAT high risk drug

Answer 9

METHOTREXATE

Question 10

How long would you tell patient to use miconazole cream for

Answer 10

use until lesions cleared

Continue treatment for 7 days (skin infections) or
10 days (nail infections) after all the symptoms have
cleared to prevent them from coming back

Question 11

How would you advice pt buying mebendazole for child

Answer 11

100mg tab

whole family (those 2+, not pregnant or breast feeding)

retreat after two weeks: only if infection RE OCCURS

Question 12

How long should a patient keep permethrin keep on

Answer 12

8- 12 hours

Permethrin should only be used on the skin or hair and scalp. Avoid getting permethrin in your eyes, nose, ears, mouth, or vagina. Do not use permethrin on your eyebrows or eyelashes. If permethrin gets in your eyes, flush them with water right away.

Question 13

Where do we apply terbinafine- just on affected area?

Answer 13

NO on surrounding area as well