potential interactions between drugs and phytomedicines

13 Pages·2013·0.61 MB·English

POTENTIAL INTERACTIONS BETWEEN
DRUGS AND PHYTOMEDICINES

Herb/Herb Group Possible Interacting Drugs Possible Interaction(s) References
Aloe Vera gel and juice O(er.agl. hgylipboegnlcylcaameimdeic) drugs Increased hypoglycaemic effects possible
Vitamin C & E Increased absorption possible 1
Reduced plasma levels in healthy males
Warfarin after 2 weeks ginseng administration 2
American Ginseng
(Panax quinqefolium) Possible potentiation of antipsychotic properties
Antipsychotics 216
suggested
Andrographis Theophylline Drug bioavailability reduced in studies on rats 3
Reduced anticancer activity implicated by in
Cisplatin vitro study involving Aloe emodin 2
Anthraquinone laxatives Potassium depletion (hypokalaemia) leading
Digoxin and other cardioactive
glycosides to increased risk of cardiac toxicity, if large 4,5
doses used.
Thiazide diuretics Potassium depletion 4,5

Anxiolytics (Valerian, Hypnotics, tranquillisers,
Additive CNS depressant effects, particularly
Kava, Passionflower, opiates, and some analgesics with large doses. 6,7
Californian Poppy, Hops acting as CNS.depressants
etc)
Anti-platelet agents
(e.g. ginger, garlic, clove, Anticoagulants (e.g. Potentiation of anticoagulant effect and
feverfew) warfarin, heparin) possible bleeding 8
Bacopa monniera Thyroxine Pefofescstisb le potentiation of thyroid hormone 9
Possible reduction in bioavailability of oral

Cyclosporin cyclosporin if co administered with large
doses Baical Skullcap 10
B(Saciucatel lSlakriual l cbaapic alensis) Etoposide Pwoosgsoinbilne potentiation of antitumour action, by 1 1
Grape seed Potentiated antioxidant effects 12
Rosuvastatin Rroesduuvcaesdta ptilna psmosas cibolen centrations of 12

Barberry Possible enhanced hypotensive effect, with
(Berberis vulgaris) Antihypertensives large doses of fruit extract. 13

Betel Nut (Areca Increased parkinsonian side effects reported
catechu) Antipsychotic drugs with flupenthixol & fluphenazine 14
Possible potentiation of anticoagulant activity,
Bilberry Warfarin with high doses 15

Oral hypoglycaemic drugs Increased hypoglycaemic effects possible, if
(e.g. chlorpropamide) large doses taken. 16,17
Bitter melon (Momordica
charantia) Reversal of multidrug resistance reported in
Vinblastine vitro 18

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Possible potentiation of thyroid hormone
Thyroxine activity 19,20
Antithyroid agents
Bladderwrack (carbimazole, propylthiouracil Possible antagonism of antithyroid hormone 19,20
(Fucus vesiculosus) etc) activity
Reduced oral drug bioavailability reported in
Amiodarone 217
rats
B(Croytoismu s scoparius) Antihypertensive drugs Pacotsivsiitbyl e interference with hypotensive 21
Use of large doses may product
B(Ruhcakmthnourns frangula) Canatridariarhcy gthlymcoics iadgeesn +ts hypokalaemia, which potentiates drug 4,5
toxicity
Antithyroid agents
Bugleweed (carbimazole, propylthiouracil Possible potentiation of anti-thyroid effects 22,23
(Lycopus virginicus; etc)
Lycopus europaeus)
Thyroxine Possible antagonism of thyroxine activity 22,23
Bupleurum spp Cproerdtinciossotneero) ids (eg Tachteioonre otfic caolr ptioctoesntetiraotiiodns of anti- inflammatory 24
B(Puetttearsbituers hybridus) Corticosteroids Easnthhamnac ed anti-inflammatory effects in 25
Possible hypokalaemia with long term

Canatshcraarqau (inaonnde o ltahxeart ives) Danigtioaxrrinh,y qthuminiicd dinreu gasn d other ltaoxxaictiitvye o uf scea,r tdhiaucs gploytceonstiidaetins ga npdos sible 4,5
antiarrhythmic agents.

Carbamazepine Increased bioavailability likely 25
Cassia auriculata

Theophylline Increased bioavailability likely
26
Antacids Possible antagonism of gastroprotective
action
Capsicum/ Reduced sailicylic acid bioavailability in rats
Cayenne pepper Aspirin following large doses of chilli 27

Theophylline Increased bioavailability possible 28

Chamomile Antihistamines Potentiation of antipruritic effects 29

Haloperidol, chlorpromazine,
Possible antagonism of antipsychotic or anti-
metoclopramide & other
emetic effects, due to possible dopaminergic 30
Chaste Tree daonptaagmoniniset sre ceptor action of Chaste Tree
(Vitex agnus-castus)
Progesterone drugs, oral Possible interference with activity of
contraceptives, HRT, hormonal drugs, by as yet unknown 31
clomiphene mechanisms

Antiarrhythmics Plasma concentration of flecainide increased 32
Antihistamines Vteerfnetnriacudilanre a rrhythmias with astemizole and 33
Cinchona bark

(containing quinine) Cardioactive glycosides Plasma concentration of digoxin increased 34

Increased plasma levels quinine due to
Cimetidine inhibition of metabolism by cimetidine. 35

Insulin Possible potentiation of hypoglycaemic effect 36
Cinnamon
Oral hypoglycaemic drugs Possible potentiation of hypoglycaemic effect

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Foot & mouth disease Enhancement of immune response to vaccine
vaccine shown in pigs 37
Cochinchina momordica
Influenza vaccination (H5N1) Enhancement of immune responses shown in 38
chickens

C(Cooleleuuss forskohlii) Aannttiipcloaategluelta angtse n&t s Pefofetecnt ttihaetioorne toicf aalnlyti cpooasgsuiblalen t or antiplatelet 39
Enhanced stimulant effects possible with
Caffeine large doses. 40
Cola
Phenytoin Irnecproeratesde din b riaobabviatsil ability of phenytoin 41

Cordyceps sinensis Gamenintoamglyyccoins &id eo tahnetri biotics Protection against nephrotoxicity in rats 86
Case reports of increased anticoagulant
Cranberry Warfarin effects, although no effects shown in healthy 43-56
volunteers
C(Cuumminin um cyminum) Rifampicin Eexnthraacntc reempoerntet do f plasma levels by aqueous 57

Vinblastine & other cytotoxics Preovsesrisbalel oefn mhaunlticderdu gc yrteostiosxtaicn ecfefe cts due to 58
Curcumin (from Turmeric)
Possible protection against alcohol- induced 59
Ethanol neurological disorders
Theoretical potentiation of diuretic effects
Dandelion leaf Diuretics with large doses
Da-Cheng-Qi
(CRithriesu amu rtaanntgiuumtic)u m, Ranitidine Increased drug bioavailability reported in rats 60
Anticoagulants Potentiation of anticoagulant effects likely 61
Dan Shen
(Salvia miltiorrhiza) Cycosporin Pparoretenctetioranl aSgaalvinias ti nn erapthsr otoxicity from 62

D(eigu rAeptiicusm graveolens) Corticosteroids Iinnccrreeaasseedd priostka assdivuemrs leo sesff (etchteso dreuteic taol only). 63
D(Aonngge Qlicuaa i Anticoagulants Tefhfeecotrse tical risk of enhanced anticoagulant 64
sinensis)

I(megm cuyncolosusppporreinses,iv tea cdrrouligmsu s) Tefhfeecotrse,t tihcaolu rgehd uncot icoans iens i mrempournteodsu. ppressive 65
Echinacea
Increased sensitivity to pharyngeal irritant
Marijuana effects of alkamide-rich liquid preparations 66
reported.
Possible antagonism of antihypertensive
Antihypertensive agents effect
CNS stimulants Sympathomimetic effects; hypertension

Digoxin and cardioactive
glycosides Arrhythmias possible
Ephedra sinica Ergotamine and oxytocin Hypertension possible
Halothane Arrhythmias possible

Monoamine oxidase inhibitors Life-threatening acute hypertensive response +
(MAOI’s) hyperpyrexia & coma possible
SSRI antidepressants Potentiation of serotonergic effects possible
Evodia rutaecarpa Theophylline Reduction in drug effects possible 67,68

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Antidiabetic agents Pacotsivsiitbyl (el aprogtee ndtoiasteiosn) of hypoglycaemic 69
Fenugreek
Hypolipidaemic agents P(laorsgseib dleo speoste) ntiation of lipid-lowering effects 70
Feverfew Anticoagulants Tefhfeecotrse tical potentiation of anticoagulant 71
Flaxseed Theoretical delay in absorption of drugs
(Linum usitatissimum) Many drugs taken simultaneously 72
Protection against cardiotoxicity from large
Adriamycin doses 73
Anticoagulants (warfarin, Possible mild potentiation of anticoagulant
phenprocoumon) effect 74,75
Gentamycin Protection against nephrotoxicity 76
Garlic
Platelet inhibitors
(dipyridamole, aspirin, Theoretical potentiation of platelet inhibitory
indomethacin etc) effects, with large doses of garlic 77
Saquinavir Rdoesdeusc eodf g palarlsicm a levels reported, with large 78
Gentian (and other bitters) Anti Peptic-ulcer agents Possible antagonism of anti-ulcer effects
Theoretical potentiation of anticoagulant
Aphnetincporaogcuoluamntosn ()w arfarin, elitftfleec ct,l iwnihceanl e hviigdhe ndcoes es ginger taken, though 79
Theoretical potentiation of antiplatelet effect,

Antiplatelet agents (eg when high doses ginger taken, though little
Ginger aspirin, dipyridamole) clinical evidence and no effect in healthy 79
volunteers
Large doses ginger may reduce bioavailability
Cyclosporin of oral cyclosporin 80
Reduced plasma levels seen in rabbits from a
Diclofenac combined ginger & pepper preparation 81
Theoretical potentiation of anticoagulant or
Anticoagulants &
antiplatelet effects, though no effect in healthy
antiplatelet agents volunteers 76,79,82
Enhanced anti-atherogenic effect suggested in
Cilostazol 219
mice
Doxorubicin Reduction in cardiotoxicity in animal studies 83
Gentamycin Pgurointeecat ipoing sa gaanidn smt iocteo toxicity reported in 84
Ginkgo Haloperidol Iamdpverorsvee de fefeffcictsa crey poof rhteadlo peridol & less 85, 86
Metformin Ssuogmgee sptoetde ntiation of hypoglycaemic action 87, 88
Midazolam Possible enhancement in drug availability 89
Reduced oral simvastatin but not simvastatin
Simvastatin acid PK bioavailability reported in healthy 220
Tolbutamide Spvoloisglushnitb taeletet ersn u ation of hypoglycaemic effect 89
Albendazole Ifnocllorewaisnegd I Ve xgcinresteionng from GIT reported 90
Caffeine Increased stimulant effects possible 91
Ginseng Digoxin Imnteearsfeurreenmceen wtsit hre cpeorrttaeind laboratory plasma 92, 93
(Panax ginseng)
Theoretical potentiation of hypoglycaemic
Hypoglycaemic drugs effects, & improvement of insulin resistance 94,82
Possible potentiation of MAOI effects,
MAOI antidepressants causing headache, mania.
Globe Artichoke Cholesterol-lowering drugs Theoretically additive effects with large doses 70

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Goji 3 case reports of potentiated anticoagulant
(Lycium barbarum) Warfarin effects 95,96,221
Golden Seal Debrisoquine Increased drug levels possible 97
Gotu Kola Adriamycin Possible protection against cardiac toxicity 98
Terfenadine Increased plasma levels reported 99
Calcium channel Increased plasma concentration and thus
blockers cardiovascular effects I 100
Chloroquine Increased plasma concentrations 101
Fexofenadine Reduced oral biovailability reported 102
Grapefruit juice Immunosuppressant s (eg

cyclosporin, tacrolimus, 100
sirolimus) Increased plasma concentrations
Many other drugs Pthousss eibffleec intsc reased plasma concentration and 10 3
Statins Increased plasma levels reported 104
Reduced anticancer effects of
Green Tea Bortezomib bortezomib reported in vitro 105
Gotuhaerr gbuumlki n(agn d Antibiotics Absorption of phenoxymethypenicillin reduced 10 6
agents)
Gymnema sylvestre Hinycpluodginlygc ainesmuilicn d rugs, Phyopsosgiblylec apeomteinct eiaftfieocnt so f 107

Dgliygcooxsinid &es o ther cardiac Iancctirveiatys,e pdo isnsoibtrloyp riecq aunirdin ogt hdeors caagred rioevdauscctiuolna.r 108
Hawthorn
Increased hypotensive effect possible, with
Hypotensive drugs large doses of hawthorn. 108
Hemidesmus indicus Gentamicin Panroimteaclt isotnu daigeasi nst nephrotoxicity shown in 109
Reduced plasma levels of carbamazepine

Carbamazepine reported following large doses honey in
rabbits 110

Honey Diltiazem Rfoellodwucinegd lpalragsem dao lseevse hlso dnieltiya ztoe rma brbepitso rted 11 1
Increased plasma levels of phenytoin reported
Phenytoin in rabbits 112
Benzodiazepines,

Hops Hanyaplngoetsicicss, ,O Tpriicoyidc lic Potentiation of sedative effects 11 3
antidepressants
Anticoagulants & antiplatelet
agents such as warfarin and Potentiation of anticoagulant effects reported. 114
aspirin
Horsechestnut
In vitro potentiation of activity against
5 – Flourouracil hepatocellular carcinoma reported for β- 115
aescin
Propylthiouracil,
methimazole & other anti- Increased thyrotoxic activity possible with large 116
Horseradish thyroid agents. doses
Possible antagonism of thyroxine activity,
Thyroxine with large doses 116

K(Maoremlao rdica charantia) Ibnigsuualinn,i dseuslp honylureas, Potentiation of hypoglycaemic effects possible 117

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Dopamine antagonists (eg
antipsychotics, Increased risk of Parkinsonian side effects 118
metoclopramide) theoretically possible.
Drugs with a risk of
hepatotoxicity Possible increased risk of hepatotoxicity 119
Additive C.N.S. depressant effects possible,
Kava Ethanol especially with large doses. 120
Ldeopvoa-mdoinpearg &ic o athgeern ts PPoasrksiinbsleo nre’sd duicsteioans eo.f efficacy of l-dopa in 11 8

Sedative drugs (hypnotics,
Additive C.N.S. depressant effects possible,
bsoemnzeo dainaazelgpeinseicss, )o piates, especially with large doses. 121
Antithyroid agents
(carbimazole, Possible interference with antithyroid activity 19,20
Kelp propylthiouracil etc)
Thyroxine Pacotsivsiitbyl e potentiation of thyroid hormone 19, 20
Kyushin (Japanese Possible interference with digoxin plasma
preparation) Digoxin assay

Possible interference with drug activity if 4,5
Antiarrhythmic drugs hypokalaemia following long term laxative
Laxative (anthraquinone- abuse
containing) herbs
Possible digoxin toxicity due to hypokalaemia
Digoxin if long term laxative abuse 4,5

Possible reduction in bioavailability & thus
Lemon Chloroquine antimalarial effects 122

Interference with hypotensive effects,
Antihypertensives with prolonged use of large doses 123
Azathioprine Lowered risk of hepatotoxicity possible 12 4
Corticosteroids Theoretical potentiation of steroidal effects

Liquorice Hypokalaemia leading to adverse
Digoxin cardiovascular effects, if large doses taken. 123

Enhanced drug clearance in rats reported for
Lignocaine Glycyrrhiza uralensis (Chinese liquorice) 125

Hypokalaemia with adverse effects especially
Thiazide and loop Diuretics likely when combined with digoxin as above 126
Doxorubicin Pefrfoetcetcst isohno awgna iinn srat mtsy ocardial adverse 12 7
Glibenclamide, metformin Improved diabetic control possible 12 8

Milk Thistle Reduced antibiotic effects possible; Silymarin
(St Mary’s Thistle) Metronidazole shown to increase clearance of 12 9
metronidazole
Increased oral drug bioavailability reported in
Rispiridone 223
rats

Myrrh Warfarin Case report of reduced anticoagulant effects 130
Enhanced parenteral and oral bioavailability
Nigella sativa Amoxycillin 218
reported in rats

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Ampicillin E&n Phraontecuesd macirtaivbitilyis a sguagingsets Ete Cd oli 13 1

Ocimum Cotrimoxazole Enhanced activity against E Coli suggested
131
gratissimum
(African basil) Ketoconazole Enhanced anti-Candida activity suggested 13 1

Nystatin Enhaced ant-Candida activity suggested 131

Atenolol, Celiprolol & possibly Reduced bioavailability following 200ml
Orange Juice other beta- blockers orange juice three times daily. 132

Sodium picosulphate &
Reduced plasma levels of paeony active
Paeony other stimulant laxatives; metabolite possible. 133-134
amoxicillin & metronidazole
Benzodiazepines, hypnotics,
Passionflower opioid analgesics, tricyclic Theoretical potentiation of sedative effects 7
antidepressants
Amoxycillin, cefotaxime
& other beta lactam Increased plasma levels possible 135
antibiotics
Pepper
Reduced plasma levels shown from
P(Pipiepre lro nniggruumm ( l(obnlagc)k. ); DNiScAloIfDen daruc g&s o ther craobmbbitisn ed pepper & ginger preparation in 136

Phenytoin, Rifampicin Increased bioavailability shown with piperine 136
Increased bioavailability reported in healthy
Pomelo Juice Cyclosporin volunteers 137
(Citrus maxima)
Tacrolimus Case report of increased plasma levels 138

Digoxin, warfarin, lithium, Decreased absorption from GIT possible,
Psyllium seed carbamazepine with simultaneously administered drugs, 139,140
& possibly other drugs though controversial

R(Geaisnhoid meurmshar oluocmid um) Bseednaztoivdeiasz eprines & other Potentiated hypnotic effects shown in rats 141
Increased oral drug bioavailability reported in
Rhodiola rosea Losartan 224
rabbits

Potassium loss and thus increased risk of
Rhubarb 4,5
Digoxin and other cardiac cardiovascular toxicity, with prolonged use or
(Rheum palmatum)
glycosides abuse
Azathioprine Ptorxoicteitcyt ion against azathioprine- induced liver 14 2

Rosemary
Enhanced intracellularaccumulation of
Chemotherapy drugs doxorubicin and vinblastine reported in-vitro 143
Protection against azathioprine- induced liver
Sage Azathioprine toxicity 144

Salboku-to (Asian herbal
mixture; contains same
herbs as ‘Sho-saiko-to’,
plus xiao chai hu tang, Prednisolone or Increased steroidal effects possible 145
Poria cocos, Magnolia prednisone
officinalis, Perillae
frutescens)

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Enhanced oral drug bioavailability reported for
Cyclosporin A 225
low but not high drug dosage in rats
Possible enhanced cytotoxic effects by

Cytotoxics large doses due to reversal of multidrug
146,147,148
resistance by gomisin A and schisandrol A
Schisandra (Schisandra
chinensis & sphenanthera) Enhanced oral bioavailability of paclitaxel
Paclitaxel
in rats 149
Enhanced oral drug bioavailability reported in
Rapamycin
healthy volunteers
Enhanced oral bioavailability shown in
Tacrolimus healthy volunteers 150

Sedative drugs (eg
Sedatives
benzodiazepines, clonidine,
(Peags Vsiaolnefrloiawne, rH) ops, Kava, opioid analgesics, Potentiation of sedative effects 7,121
phenobarbitone)
Cardiac glycosides &
Senna antiarrhythmics (eg Hypokalaemia leading to increased risk of 4,5
(Cassia spp) quinidine) cardiac toxicity.
S(Peonlyeggaal a senega) Hypoglycaemic drugs Pefofescstisb le enhancement of hypoglycaemic 15 1
Shankhapushpi Decreased phenytoin concentrations, loss
(Ayurvedic preparation) Phenytoin of seizure control 152
“Sho-saiko-to” Reduced plasma levels measured in rats
(Minor Bupleurum) Carbamazepine after large doses 153
Siberian Ginseng
Interference with certain laboratory serum
(sEelnetuicthoesruosc)o ccus Digoxin digoxin measurements reported 154
Theoretical reduction in absorption & thus
Slippery Elm Various drugs clinical effects
Sophora flavescens Theoretical enhancement of effects through
(Kushen) Various drugs inhibition of CYP450 3A4 155
Amitriptyline & nortriptyline Panotsidseibplere rsesdaunctt ieofnfe icnt sp lasma levels and thus 15 6
Rduced hypocholesterolaemic effect
Atorvastatin possible 157
Theoretical reduction in plasma levels,
Carbamazepine though no effects in a volunteer study. 158
Possible protection against cisplatin
Cisplatin nephrotoxicity by pre- treatment with large 159
doses.

Possible reduction in plasma immuno-
Cyclosporin, tacrolimus
& other immunosuppressants suppressant levels, & thus compromised 160
treatment/ transplant rejection.
Possible reduction in plasma levels & thus
St John’s Wort Daunorubicin failure of cytotoxic effect. 161
Possible reduction in plasma digoxin levels,
Digoxin and thus therapeutic failure 162
Possible reduced plasma levels & thus
Docetaxel failure of cytotoxic effect. 163
Reduction of plasma levels & thus
Fexofenadine antihistaminic effects 164
Gliclazide Reduced plasma levels possible 165
Possible reduced plasma levels & thus
Imatinib mesylate failure of cytotoxic effects 166
Indinavir, saquinavir, ritonavir
Possible reduction in plasma levels, &
& other protease inhibitor thus failure of antiviral effect. 167
antivirals

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Reduced plasma levels of active metabolite
Irinotecan SN-38 in cancer patients reported. 168,169

Ivabradine Reduced plasma levels possible 170

Theoretical possibility of serious serotonin
MAOI’s syndrome, though no cases reported

Case reports of reduced plasma levels in 2
Methadone methadone maintenance patients 171

Midazolam Reduced plasma levels in volunteer study 17 2

Morphine Potentiated antinociceptive effects reported 173
in mice

Nevirapine Reduced plasma levels reported 174

St John’s Wort Nifedipine Reduced plasma levels reported 175
continued… Omeprazole Reduced plasma levels reported 176
Increased breakthrough bleeding possible;
case reports of unwanted pregnancies
Oral contraceptives though no evidence of reduced efficacy 177,178,179
from 3 controlled studies
Oxycodone Pthousss aibnlael rgeedsuicc teioffne cint plasma levels and 18 0
Phenobarbitone Theoretical reduction in plasma levels 18 1
Phenprocoumon Refefedcutcse d plasma levels & thus anticoagulant 18 2
Phenytoin Theoretical reduction in plasma levels. 18 1

Single dose of SJW increases
Procainamide procainamide plasma levels in mice 183

Quazepam Reduced plasma levels possible
184

Reduced plasma concentrations
Simvastatin & thus hypocholesterolaemic effects 185

SSRI antidepressants (eg Theoretical possibility of serious serotonin
fluoxetine, sertraline, syndrome, though few case reports to
paroxetine) date
Talinolol Reduced plasma levels possible 186
Tacrolimus Rtraendsupcleadn tp plaastimenat sle vels reported in renal 187, 188
Tolbutamide Increased incidence of hypoglycaemia 18 2
Triptans (sumatriptan,
Theoretical possibility of serotonin
naratriptan, rizatriptan, syndrome, though no case reports to date
zolmitriptan)
Reduced bioavailability reported in healthy
Verapamil volunteers 189

Warfarin Possible reduction in anticoagulant effect 190,191

Zolpidem Reduced plasma drug levels reported 192

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ACE inhibitors Severe hypertension 193
Anaesthetics Arrhythmia 194
Antidepressants Hypertensive crises with MAOIs; 195,196
hypertension, arrhythmias with tricyclics

Antihypertensives Antagonism, hypertension (possibly
Sympathomimetics Antipsychotics Beta-blockers severe) 197,193
(e.g. ephedrine and
pseudoephedrine from Bronchodilators Potentiation
Ephedra spp) Diuretics Increased risk of hypokalaemia 19 8
Dopaminergics Increased risk of toxicity with bromocriptine 119939
Sympathomimetics Potentiation and hypertension
Vasoconstrictor Increased vasopressor effects 19 7
Choroquine Rine hdeuacltehdy c vhololuronqteueinrse bioavailability shown 129070
Tamarind Increased ibuprofen bioavailability shown in
(Tamarindus indica) Ibuprofen healthy volunteers 201
Iron, Zinc, Calcium & mineral Possible reduced mineral absorption from
preparations GIT 202
Tannin-rich agents Many drugs Theoretical reduction in absorption from
GIT, although virtually no evidence to date
Possible reduced protein absorption from
Protein rich preparations GIT
Tetracycline-based & possibly Potentiation of antibiotic effects against
Thyme β-lactam-based antibiotics MRSA possible with large doses 203
Trikatu (Ayurvedic Ibuprofen Reduced bioavailability reported in rabbits 13 6
preparation containing

ginger, black pepper, and Rifampicin Rate but not extent of bioavailability
Piper longum) reduced in rabbits 204
Platelet inhibitors (eg aspirin,
Turmeric dAinptyicriodaagmuolalen)t sa n(wda rfarin) Pwoitshs hibigleh pdootseensti aotfi otunr mofe arnict ioprla ctuerlecut emffine ct 20 5
U(Azyaurrav reodoict preparation) Digoxin Interference with digoxin plasma assay 20 6
Benzodiazepines, hypnotics,
Potentiation of sedative effects &
Valerian tarnicaylgcleics iacsn,t i daenpareesstshaentitcss, opioid prolongation of anaesthesia 207
Vasoconstrictors Antihypertensives Antagonism 21
(e.g. Broom) Sympathomimetics Hypertension
Vasodilators(eg Hawthorn) Antihypertensives Additive effects

Anticoagulants Vitamin K antagonizes
Folic acid occasionally reduces plasma
Anticonvulsants concentration; vitamin D requirements 208
Vitamins increased
Diuretics HD yspueprpclaelmcaeenmtaiati owni th thiazides and vitamin 20 9
Dopaminergics Levodopa antagonized with pyridoxine 211
Theoretical potentiation of anticoagulant
Willow bark Anticoagulants effects with large doses
Antidepressants, selective
Plasma concentration of xanthines
X(ea.gn.t hCinoela-,r iGchu areramnead,i Mesa te) s(SeSroRtoIsn)i n reuptake inhibitors increased 21 3
Antihypertensives Antagonism of hypotensive effect possible. 214
Y(Poahuimsinbyes t alia yohimbe) Antihypertensives Antagonism of hypotensive effect possible. 21 5

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