Penicillamine(continued)
▶Iron (oral)is predicted to decrease the absorption of
penicillamine. Separate administration by at least 2 hours.
nStudy
▶Sodium aurothiomalatepotentially increases the risk of side-
effects when given withpenicillamine(in those who have had
previous adverse reactions to gold). Avoid.rStudy
▶Zincis predicted to decrease the absorption ofpenicillamine.
nTheoretical
Penicillins→seeTABLE 1p. 847 (hepatotoxicity)
amoxicillin.ampicillin.benzylpenicillin.flucloxacillin.
phenoxymethylpenicillin.piperacillin.pivmecillinam.temocillin.
ticarcillin..
▶Allopurinolincreases the risk of skin rash when given with
penicillins(amoxicillin, ampicillin).oStudy
▶Antiepileptics(valproate)increase the risk of side-effects when
given withpivmecillinam. Avoid.rAnecdotal
▶Penicillinspotentially alter the anticoagulant effect of
coumarins. Monitor INR and adjust dose.rAnecdotal
▶Penicillinsare predicted to increase the risk of toxicity when
given withmethotrexate.rTheoretical→Also seeTABLE 1
p. 847
▶Piperacillinincreases the effects ofneuromuscular blocking
drugs, non-depolarising.oStudy
▶Penicillinsare predicted to increase the risk of bleeding events
when given withphenindione.rTheoretical
▶Piperacillinincreases the effects ofsuxamethonium.o
Study
Pentamidine→seeTABLE 15p. 850 (myelosuppression),TABLE 2p. 847
(nephrotoxicity),TABLE 9p. 849 (QT-interval prolongation)
▶Didanosineis predicted to increase the risk of pancreatitis
when given withpentamidine. Avoid.rStudy
▶Intravenouspentamidinepotentially increases the risk of QT-
prolongation when given withdrugs that prolong the QT
interval.rAnecdotal
▶Foscarnetincreases the risk of hypocalcaemia when given with
pentamidine.rAnecdotal→Also seeTABLE 2p. 847
Pentazocine→see opioids
Pentostatin→seeTABLE 15p. 850 (myelosuppression),TABLE 5p. 847
(thromboembolism)
▶Alkylating agents(cyclophosphamide)(high-dose) increase the
risk of toxicity when given withpentostatin. Avoid.r
Anecdotal→Also seeTABLE 15p. 850→Also seeTABLE 5p. 847
▶Fludarabineincreases the risk of pulmonary toxicity when
given withpentostatin. Avoid.rStudy→Also seeTABLE 15
p. 850
Pentoxifylline
▶Pentoxifyllineis predicted to increase the concentration of
aminophylline. Use with caution or avoid.rTheoretical
▶Quinolones(ciprofloxacin)very slightly increase the exposure
topentoxifylline.oStudy
▶SSRIs(fluvoxamine)are predicted to increase the exposure to
pentoxifylline.oTheoretical
▶Pentoxifyllineincreases the concentration oftheophylline.
Monitor and adjust dose.rStudy
Peppermint oil
▶Peppermint oilis predicted to increase the exposure to
lomitapide. Separate administration by 12 hours.o
Theoretical
Perampanel→see antiepileptics
Pergolide→see dopamine receptor agonists
Pericyazine→see phenothiazines
Perindopril→see ACE inhibitors
Perphenazine→see phenothiazines
Pertuzumab→see monoclonal antibodies
Pethidine→see opioids
Phenelzine→see monoamine-oxidase A and B inhibitors, irreversible
Phenindione→seeTABLE 3p. 847 (anticoagulant effects)
FOOD AND LIFESTYLEThe effects of phenindione can be
reduced or abolished by vitamin K, including that found in
health foods, food supplements, enteral feeds, or large
amounts of some green vegetables or green tea. Major
changes in diet (especially involving salads and vegetables)
and in alcohol consumption can affect anticoagulant control.▶Antiarrhythmics(propafenone)are predicted to increase the
anticoagulant effect ofphenindione. Monitor and adjust dose.
oTheoretical
▶Antifungals, azoles(miconazole)greatly increase the
anticoagulant effect ofphenindione.rTheoretical
▶Axitinibis predicted to increase the risk of bleeding events
when given withphenindione.rTheoretical
▶Bosutinibis predicted to increase the risk of bleeding events
when given withphenindione.rTheoretical
▶Cabozantinibis predicted to increase the risk of bleeding
events when given withphenindione.rTheoretical
▶Cephalosporins(ceftriaxone)potentially increase the risk of
bleeding events when given withphenindione.rAnecdotal
▶Corticosteroidsare predicted to increase the effects of
phenindione.oAnecdotal
▶Crizotinibis predicted to increase the risk of bleeding events
when given withphenindione.rTheoretical
▶Dasatinibis predicted to increase the risk of bleeding events
when given withphenindione.rTheoretical
▶Disulfiramis predicted to increase the anticoagulant effect of
phenindione.rTheoretical
▶Enteral feeds(vitamin-K containing) potentially decrease the
effects ofphenindione.rTheoretical
▶Erlotinibis predicted to increase the risk of bleeding events
when given withphenindione.rTheoretical
▶Fibratesare predicted to increase the anticoagulant effect of
phenindione. Monitor INR and adjust dose.rStudy
▶Gefitinibis predicted to increase the risk of bleeding events
when given withphenindione.rTheoretical
▶H 2 receptor antagonists(cimetidine)increase the exposure to
phenindione.rAnecdotal
▶Imatinibis predicted to increase the risk of bleeding events
when given withphenindione.rTheoretical
▶Lapatinibis predicted to increase the risk of bleeding events
when given withphenindione.rTheoretical
▶Nandroloneis predicted to increase the anticoagulant effect of
phenindione. Monitor and adjust dose.rTheoretical
▶Nilotinibis predicted to increase the risk of bleeding events
when given withphenindione.rTheoretical
▶Oxymetholoneincreases the anticoagulant effect of
phenindione.rAnecdotal
▶Paracetamolis predicted to increase the anticoagulant effect
ofphenindione.rTheoretical
▶Pazopanibis predicted to increase the risk of bleeding events
when given withphenindione.rTheoretical
▶Penicillinsare predicted to increase the risk of bleeding events
when given withphenindione.rTheoretical
▶Ponatinibis predicted to increase the risk of bleeding events
when given withphenindione.rTheoretical
▶Ranibizumabis predicted to increase the risk of bleeding
events when given withphenindione.rTheoretical
▶Regorafenibis predicted to increase the risk of bleeding events
when given withphenindione.rTheoretical
▶Ruxolitinibis predicted to increase the risk of bleeding events
when given withphenindione.rTheoretical
▶Sorafenibis predicted to increase the risk of bleeding events
when given withphenindione.rTheoretical
▶Statins(rosuvastatin)are predicted to increase the
anticoagulant effect ofphenindione. Monitor INR and adjust
dose.rTheoretical
▶Sunitinibis predicted to increase the risk of bleeding events
when given withphenindione.rTheoretical
▶Vandetanibis predicted to increase the risk of bleeding events
when given withphenindione.rTheoretical
Phenobarbital→see antiepileptics
Phenothiazines→seeTABLE 8p. 848 (hypotension),TABLE 9p. 849
(QT-interval prolongation),TABLE 11p. 849 (CNS depressant effects),
TABLE 10p. 849 (antimuscarinics)chlorpromazine.fluphenazine.levomepromazine.pericyazine.
perphenazine.prochlorperazine.promazine.trifluoperazine..▶Chlorpromazinedose adjustment might be necessary if
smoking started or stopped during treatment.
▶Fluphenazinedose adjustment might be necessary if
smoking started or stopped during treatment.972 Penicillamine—Phenothiazines BNFC 2018 – 2019
Interactions|Appendix 1A1