other phosphodiesterase inhibitors (for example, milrinone, cilostazole,
roflumilast) is limited.
7.2 Pharmacokinetic Interactions with Adempas
Smoking: Plasma concentrations in smokers are reduced by 50-60%
compared to nonsmokers. Based on pharmacokinetic modeling, for patients
who are smokers, doses higher than 2.5 mg three times a day may be
considered in order to match exposure seen in nonsmoking patients.
Safety and effectiveness of Adempas doses higher than 2.5 mg three times
a day have not been established. A dose reduction should be considered
in patients who stop smoking [see Dosage and Administration (2.4) and
Clinical Pharmacology (12.3)].
Strong CYP and P-gp/BCRP inhibitors: Concomitant use of riociguat
with strong cytochrome CYP inhibitors and P-gp/BCRP inhibitors such
as azole antimycotics (for example, ketoconazole, itraconazole) or HIV
protease inhibitors (such as ritonavir) increase riociguat exposure and may
result in hypotension. Consider a starting dose of 0.5 mg 3 times a day
when initiating Adempas in patients receiving strong CYP and P-gp/BCRP
inhibitors. Monitor for signs and symptoms of hypotension on initiation and
on treatment with strong CYP and P-gp/BCRP inhibitors. A dose reduction
should be considered in patients who may not tolerate the hypotensive effect
of riociguat [see Dosage and Administration (2.5), Warnings and Precautions
(5.3) and Clinical Pharmacology (12.3)].
Strong CYP3A inducers: Strong inducers of CYP3A (for example, rifampin,
phenytoin, carbamazepine, phenobarbital or St. John’s Wort) may
significantly reduce riociguat exposure. Data are not available to guide
dosing of riociguat when strong CYP3A inducers are co-administered [see
Clinical Pharmacology (12.3)].
Antacids: Antacids such as aluminum hydroxide/magnesium hydroxide
decrease riociguat absorption and should not be taken within 1 hour of
taking Adempas [see Clinical Pharmacology (12.3)].
8 USE IN SPECIFIC POPULATIONS
8.1 Pregnancy
Pregnancy Category X
Risk Summary
Adempas may cause fetal harm when administered to a pregnant woman
and is contraindicated during pregnancy. Adempas was teratogenic and
embryotoxic in rats at doses with exposures to unbound drug that were
approximately 8 times and 2 times, respectively, the human exposure. In
rabbits, riociguat led to abortions at 4 times the human exposure and fetal
toxicity with exposures approximately 13 times the human exposure. If
Adempas is used in pregnancy, or if the patient becomes pregnant while
taking this drug, apprise the patient of the potential hazard to the fetus [see
Boxed Warning and Contraindications (4.1)].
Animal Data
In rats administered riociguat orally (1, 5, and 25 mg/kg/day) throughout
organogenesis, an increased rate of cardiac ventricular-septal defect was
observed at the highest dose tested. The highest dose produced evidence
of maternal toxicity (reduced body weight). Post-implantation loss was
statistically significantly increased from the mid-dose of 5 mg/kg/day. Plasma
exposure at the lowest dose in which no adverse effects were observed is
approximately 0.4 times that in humans at the maximally recommended
human dose (MRHD) of 2.5 mg three times a day based on area under
the time-concentration curve (AUC) for unbound drug in rat and humans.
Plasma exposure at the highest dose (25 mg/kg/day) is approximately 8
times that in humans at the MRHD while exposure at the mid-dose (5 mg/kg/
day) is approximately 2 times that in humans at the MRHD. In rabbits given
doses of 0.5, 1.5 and 5 mg/kg/day, an increase in spontaneous abortions
was observed starting at the middle dose of 1.5 mg/kg, and an increase in
resorptions was observed at 5 mg/kg/day. Plasma exposures at these doses
were 4 times and 13 times, respectively, the human exposure at the MRHD.
8.3 Nursing Mothers
It is not known if Adempas is present in human milk. Riociguat or its
metabolites were present in the milk of rats. Because many drugs are present
in human milk and because of the potential for serious adverse reactions in
nursing infants from riociguat, discontinue nursing or Adempas.
8.4 Pediatric Use
Safety and effectiveness of Adempas in pediatric patients have not been
established [see Nonclinical Toxicology (13.2)].
8.5 Geriatric Use
Of the total number of subjects in clinical studies of Adempas, 23% were 65
and over, and 6% were 75 and over [see Clinical Studies (14)]. No overall
differences in safety or effectiveness were observed between these subjects
and younger subjects, and other reported clinical experience has not identified
differences in responses between the elderly and younger patients, but greater
sensitivity of some older individuals cannot be ruled out.
Elderly patients showed a higher exposure to Adempas [see Clinical
Pharmacology (12.3)].
8.6 Females and Males of Reproductive Potential
Pregnancy Testing: Female patients of reproductive potential must have a
negative pregnancy test prior to starting treatment with Adempas, monthly
during treatment, and one month after discontinuation of treatment with
Adempas. Advise patients to contact their healthcare provider if they become
pregnant or suspect they may be pregnant. Counsel patients on the risk to
the fetus [see Boxed Warning, Dosage and Administration (2.3) and Use in
Specific Populations (8.1].
Contraception: Female patients of reproductive potential must use acceptable
methods of contraception during treatment with Adempas and for 1 month
after treatment with Adempas. Patients may choose one highly effective form
of contraception (intrauterine devices [IUD], contraceptive implants or tubal
sterilization) or a combination of methods (hormone method with a barrier
method or two barrier methods). If a partner’s vasectomy is the chosen
method of contraception, a hormone or barrier method must be used along
with this method. Counsel patients on pregnancy planning and prevention,
including emergency contraception, or designate counseling by another
healthcare provider trained in contraceptive counseling [See Boxed Warning].
8.7 Renal Impairment
Safety and efficacy have not been demonstrated in patients with creatinine
clearance <15 mL/min or on dialysis [see 6Ɩ