Pharmacokinetics and Pharmacodynamic Interactions Flashcards
What is a pharmacokinetic interaction?
A drugs affects the ADME of another drug.
What is a pharmacodynamic interaction?
The effects of one drug are changed by the presence of another drug at its pharmacological site of action.
Interactions between drugs with similar or antagonistic pharmacological effects or S/Es
Enzyme inductions takes how long to wear off?
2-3 weeks
What does CRAP GPs SBS stand for?
Inducers.
Carbamazepine. Rifampicin Alcohol Phenytoin Griseofulvin Phenobarbital Sulphonylureas
St Johns Wort
Barbituates
Smoking
Enzyme inhibition typically takes how long to wear off?
A few days
What does SICKFACES.COM.GF stand for?
Inhibitors Sodium Valproate Isoniazid Cimetidine Ketoconazole Fluconazole Alcohol Chloramphenicol Erythro/Clarithro Sulphonamides Ciprofloxacin Omeprazole Metronidazole
Grapefruit
Fluoxetine
What does the C stand for in CRAP GPs SBS? (inducers)
Inducers.
>>Carbamazepine<< Rifampicin Alcohol Phenytoin Griseofulvin Phenobarbital Sulphonylureas
St Johns Wort
Barbituates
Smoking
What does the R stand for in CRAP GPs SBS? (inducers)
Inducers.
Carbamazepine. >>Rifampicin<< Alcohol Phenytoin Griseofulvin Phenobarbital Sulphonylureas
St Johns Wort
Barbituates
Smoking
What does the A stand for in CRAP GPs SBS?
Alcohol:
Inducers.
Carbamazepine. Rifampicin Alcohol Phenytoin Griseofulvin Phenobarbital Sulphonylureas
St Johns Wort
Barbituates
Smoking
What do the P’s stand for in CRAP GPs SBS (inducers)?
Phenytoin and phenobarbital
Inducers.
Carbamazepine. Rifampicin Alcohol Phenytoin Griseofulvin Phenobarbital Sulphonylureas
St Johns Wort
Barbituates
Smoking
What do the S’s stand for in CRAP GPs SBS (inducers)?
Sulphonylureas
St Johns Wort
Smoking
Inducers.
Carbamazepine. Rifampicin Alcohol Phenytoin Griseofulvin Phenobarbital Sulphonylureas
St Johns Wort
Barbituates
Smoking
What do the S’s stand for in SICKFACES.COM.GF?
Inhibitors:
Sodium valproate
Sulphonamides
Sodium Valproate Isoniazid Cimetidine Ketoconazole Fluconazole Alcohol Chloramphenicol Erythro/Clarithro Sulphonamides Ciprofloxacin Omeprazole Metronidazole
Grapefruit
Fluoxetine
What do the C’s stand for in SICKFACES.COM.GF?
Cimetidine
Chloramphenicol
Ciprofloxacin
Sodium Valproate Isoniazid Cimetidine Ketoconazole Fluconazole Alcohol Chloramphenicol Erythro/Clarithro Sulphonamides Ciprofloxacin Omeprazole Metronidazole
Grapefruit
Fluoxetine
What does the COM stand for in SICKFACES.COM,GF?
Sodium Valproate Isoniazid Cimetidine Ketoconazole Fluconazole Alcohol Chloramphenicol Erythro/Clarithro Sulphonamides Ciprofloxacin Omeprazole Metronidazole
Grapefruit
Fluoxetine
What does the GF stand for in SICKFACES.COM.GF?
Sodium Valproate Isoniazid Cimetidine Ketoconazole Fluconazole Alcohol Chloramphenicol Erythro/Clarithro Sulphonamides Ciprofloxacin Omeprazole Metronidazole
Grapefruit
Fluoxetine
What is the interaction between alcohol and MAOI?
Tyramine = hypertensive crisis when taken with MAOI
What drugs are so enzyme inducing that an IUD is recommended for effective contraception in women using them?
Rifampicin and Rifabutin are such potent enzyme inducers that IUD is
always recommended.
he effectiveness of combined oral contraceptives is considerably reduced by
interaction with enzyme inducing drugs because they increase metabolism of the
contraceptives. Such as what?
Enzyme inducers: Carbamazepine, Phenobarbital, Primidone,
Phenytoin, Topiramate, Ritonavir, Griseofulvin, Rifampicin, Rifabutin, St John’s Wor
For Women taking enzyme inducers, additional precautions should be used for how long after stopping the inducers?
Additional contraceptive precautions should be taken for at least 4 to 8 weeks after
stopping treatment. A ‘tricycling’ method whereby daily intake of 50mcg
ethinylestradiol (unlicensed) 3 or 4 packs in a row without a break and then having a 4
day pill free interval can be used by women treated with these drugs but effectiveness
is uncertain.
Pseudoephedrine + MAOI results in what?
Hypertensive crisis
Pseudoephedrine + BBs results in?
Increased risk of hypertension
Orlistat + amiodarone results in?
May reduce amiodarone serum level.
Orlistat + anticoagulants may result in?
Variable anticoagulant effect of coumarins.
Orlistat + ciclosporin interaction
Reduced absorption of ciclosporin, black dot interaction.
What drugs come with warning cards?
- Insulin
- Lithium
- MAOis
- Oxygen
- Steroids
- Warfarin
What drugs can cause drug induced photosensitivity? (6)
Amiodarone Chlopromazine Doxycyline Fibrates Trazam gel Azapropazone
What important interaction does Garlic cause?
Increases platelet activity
What important interaction does soya have?
Enzyme inhibitor
Clozapine, haloperidol, olanzapine, caffeine, phenytoin, zafilukast, warfarin impacted.
What is the interaction between Ginger and anticoagulants?
Ginger inhibits thromboxane synthesis
Grapefruit inhibits which enzyme?
CYP3A4
What are some of the most commonly impacted drugs by grapefruit juice? (10) [Not an exhaustive list]
- Amiodarone
- Simvastatin
- CCB
- Sildenafil
- Diazepam
- Fluvoxamine
- Ritonavir
- Buspirone
- Midazolam
- Carbamazepine
