PC707 Final Safety Exam Questions and
Answers with Verified Solutions | Latest
Updated 2026
Tetracycline PRE: Photosensitivity, do not take with
milk
CONTRX: Not in pregnancy, not in
children under
8yo (unless indication such as Rocky
Mountain
Spotted fever)
***Teeth discoloration, deposition on
bones, bone
growth restrictions
Vitamin A Caution: Pregnancy, childbearing age
***Can be teratogenic in excess
Grapefruit Juice CYP-3A4 inhibitor!
Leads to increased pharmacologic effect of
drugs
(i.e. statins, some BP meds, Viagra)
Phenobarbitol CYP-2A's CYP-2C's inducer
Leads to decreased pharmacologic effects
of
several drugs
,Tegretol Caution taking concurrently with estrogen
OCPs
Caution in pregnancy
Increases CYP-450 system and increases
metabolism and excretion of estrogen,
increasing
risk of pregnancy
Warfarin Caution stopping prior to surgery when
also on
Dilantin
Caution with fluconazole (Diflucan),
TMP-SMZ
(Bactrim),
Increases open protein binding sites,
reducing
free-drug levels of Dilantin, increasing risk
for
seizure
98% of warfarin is protein bound any other
protein
binding drugs can essentially double
concentration
of free warfarin - May increase bleeding
time
Rifampin / Griseofulvin Caution with combined OCPs
CYP-450 inducer, leading to increased
clearance
of COC
, Combined Oral Contraceptive Caution with anticonvulsants (lamotrigine),
(COC) theophylline, Valium, TCAs, lithium
CYP-450 inducer - may increase
anticonvulsant
(etc.) dose while active COC, but if COC
has 7 days
placebo, then lamotrigine will return to
normal
dose
Antiretrovirals Caution with COCs
May increase or decrease COC - may
increase side
effects of estrogen or decrease overall
effectiveness
Drospirenone (Yasmin) - COC Caution with K+ sparing diuretics, ACE
inhibitors,
ARBs, heparin, NSAIDs
May cause hyperkalemia with concurrent
use -
check K+ levels during first cycle of
therapy
St. John's Wort Caution with COC
Decreases blood levels of COC hormones
Warfarin Caution with TMP-SMX (Bactrim),
acetaminophen,
prednisone
Answers with Verified Solutions | Latest
Updated 2026
Tetracycline PRE: Photosensitivity, do not take with
milk
CONTRX: Not in pregnancy, not in
children under
8yo (unless indication such as Rocky
Mountain
Spotted fever)
***Teeth discoloration, deposition on
bones, bone
growth restrictions
Vitamin A Caution: Pregnancy, childbearing age
***Can be teratogenic in excess
Grapefruit Juice CYP-3A4 inhibitor!
Leads to increased pharmacologic effect of
drugs
(i.e. statins, some BP meds, Viagra)
Phenobarbitol CYP-2A's CYP-2C's inducer
Leads to decreased pharmacologic effects
of
several drugs
,Tegretol Caution taking concurrently with estrogen
OCPs
Caution in pregnancy
Increases CYP-450 system and increases
metabolism and excretion of estrogen,
increasing
risk of pregnancy
Warfarin Caution stopping prior to surgery when
also on
Dilantin
Caution with fluconazole (Diflucan),
TMP-SMZ
(Bactrim),
Increases open protein binding sites,
reducing
free-drug levels of Dilantin, increasing risk
for
seizure
98% of warfarin is protein bound any other
protein
binding drugs can essentially double
concentration
of free warfarin - May increase bleeding
time
Rifampin / Griseofulvin Caution with combined OCPs
CYP-450 inducer, leading to increased
clearance
of COC
, Combined Oral Contraceptive Caution with anticonvulsants (lamotrigine),
(COC) theophylline, Valium, TCAs, lithium
CYP-450 inducer - may increase
anticonvulsant
(etc.) dose while active COC, but if COC
has 7 days
placebo, then lamotrigine will return to
normal
dose
Antiretrovirals Caution with COCs
May increase or decrease COC - may
increase side
effects of estrogen or decrease overall
effectiveness
Drospirenone (Yasmin) - COC Caution with K+ sparing diuretics, ACE
inhibitors,
ARBs, heparin, NSAIDs
May cause hyperkalemia with concurrent
use -
check K+ levels during first cycle of
therapy
St. John's Wort Caution with COC
Decreases blood levels of COC hormones
Warfarin Caution with TMP-SMX (Bactrim),
acetaminophen,
prednisone
