Download - DRUG_–_FOOD_-_HERBA_dd
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 1/60
DRUG – FOOD - HERBAL
INTERACTION
Prof..M.Aris Widodo
Program s2 biomedik DD
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 2/60
BANYAK OBAT OBAT BARU YANG DIKENALKAN., FDA MENYETUJUI
21 MOLEKUL OBAT BARU / TAHUN
SETIAP ORANG MENDAPAT 6 RESEP PERTAHUN
MANULA >65 TAHUN YANG JUMLAHNYA 12 % DARI POPULASI
MENGHABISKAN 30% PEMBELAJAAN OBAT
MANULA DI AMERIKA MENERIMA RATA 15 RESEP PERTAHUN
PASIEN YANG DIRAWAT DI RS MENERIMA 15 KALI PENGOBATAN/HARI
2/3 DOKTER YANG MELAKUKAN KUNJNGAN MENULIS SATU RESEP
64 % PENGGUNAAN ANTIBIOTIK DI RUMAH SAKIT TIDAK DIPERLUKAN
EFEK SAMPIMG OBAT MENINGKAT DENGAN BANYAKNYA OBAT
5% PENDERITA MRS OLEH KARENA EFEK SAMPING OBAT
EFEK AMPING OBAT SERING TERJADI PADA MANULA
BANYAK PENULISAN VITAMIN YANG SEBENARNYA TIDAK PERLU.
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 3/60
PREVALENSI INTERAKSI OBAT
MENINGKAT PADA PRAKTEK POLIFARMASI
DATA DARI MAY 1977:
JUMLAH MACAM OBAT YANG DIBERIKAN
0-5 6-10 11-15 16-20
JUMLAH PASIEN 4009 3861 1713 641
JUMLAH E.S. 142 397 478 347
RATE E.S. 4% 10% 28% 54%
POLIFARMASI BANYAK PADA MANULA
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 4/60
The “Prescribing Cascade”
•Common cause of polypharmacy inelderly
•Some common examples –NSAIA ->HTN->antihypertensive therapy
–Metoclopromide ->Parkinsonism ->Sinemet
–Dihydropyridine -> edema ->furosemide
–NSAIA ->H2 blocker ->delirium ->haldol
–HCTZ ->gout->NSAIA ->2nd antihypertensive
–Sudafed ->urinary retention ->alpha blocker
– Antipsychotic ->akithesia ->more meds
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 5/60
Prescription Drugs
•Elderly account for 1/3 of prescription drug use, while only
13% of the population
•Ambulatory elderly fill between 9-13prescriptions a year (new and refills)
•One survey: Average of 5.7
prescription medicines per patient•Average nursing home patient on 7
medicines
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 6/60
Non-prescription Drugs
•Surveys indicate that elders take average of
2-4 nonprescription drugs daily
•Laxatives used in about 1/3-1/2 of elders -
many who are not constipated•Non-steroidal anti-inflammatory medicines,
sedating antihistamines, sedatives, and H2
blockers are all available without a
prescription, and all may cause major side
effects
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 7/60
Adverse Drug Reactions
•About 15% of hospitalizations in the
elderly are related to adverse drug
reactions
•The more medications a person is
on, the higher the risk of drug-drug
interactions or adverse drug
reactions
•The more medications a person is
on, the higher the risk of non-
adherence
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 8/60
Makanan minuman
Vitamin and mineral
supplementsHerbal remedies
Nutritional supplements
Over-the-counter medications
INTERAKSI
Berbagai obat yangdigunakan unuk terapi dan
Pencegahan penyakit
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 9/60
TIPE INTERAKSI OBAT
.1Drug-Drug Pharmacokinetic
.2Drug-Drug Pharmacodynamic
.3Drug-Food/Nutrient
.4Drug-Disease
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 10/60
Interaksi obat
interaksi farmakodinami
interaksi farmakoinetik
interaksi diluar tubuh
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 11/60
Interaksi obat dengan obat, herbal atau makanan
Secara farmakodnami terjadi perubahan efek oleh karena bahan yang
Ber interaksi bekerj a pada reseptor yang sama atauyang berbeada
Akibatnya terjadi efek obat yang meningkat atau menurun
Interaksi obat dengan obat, herbal atau makanan
Secara farmako kinetik terjadi perubahan efek oleh karena bahan yang
Ber interaksi menurunkan atau meningkatkan kadar obat melalui proses
absorbsi, distribusi Metabolisme dan ekskresi sehingga terjadi efek obat
Yang meningkat atau menurun
Interaksi obat dengan obat, herbal atau makanan
Diluar tubuh menyebaban perbahan sifat fisiko kimia obat sehingga
terjadi efek Obat yang berkurang aupun efek toksik
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 12/60
R1
R1a
R2
EFFEK
OBAT-HERBAL-MAKANAN
INTERAKSI FARMAKODINAMI
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 13/60
INTERAKSI FARMAKOKINETIK
OBAT MEMPENGARUHI PROSES
ABSORBSI
DISTRIBUSI
METABOLISME
EKSKRESI
KADAR OBAT DALAMDARAH TARGET
MENINGKAT ATAU
MENURUN
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 14/60
Pharmacokinetics Pharmacodynamics
Dosage
Regimen EffectsPlasmaConcen
tration
Site of
Action
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 15/60
K
O
N
S
E N
T
R
S
I
O
B
A
T
PL
A
S
M
A
MINIMUM TOXIC CONCENTRATION
MINIMUM EFFECTIV CONCENTRATION
AUC AUC
AREA UNDER CURVE = AUC
AREA UNDER CURVE PEMBERIAN DOSIS BERULANG
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 16/60
TERAPI SUKSES REGIMEN A
KEGAGALAN TERAPI REGIMEN B
KEGAGALAN TERAPI
WAKTU PEMBERIAN OBAT
K
O
N
S
E N
T
R
S
I
O
B
A
T
PL
A
S
M
A
MINIMUM TOXIC CONCENTRATION
MINIMUM EFFECTIV CONCENTRATION
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 17/60
INTERAKSI FARMAKODINAMI
OBAT DAN OBAT
INTERAKSI FARMAKOKNETIK
OBAT DENGAN OBAT
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 18/60
Drug-Drug Interactions Affecting
Absorption and Distribution
Precipitant Drug(s)Object Drug(s)Outcome
Antacids, IronTetracycline, Ciprofloxacin
abs.
Chloral hydrateWarfarin
Pl con
•Generally absorption and distribution drug-drug-
interactions are not clinically important.
Drugs & Aging 1998;12:485-94
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 19/60
Hepatic Metabolism
)450Phase I (CYP
•Oxidation
hydroxylation
dealkylationsulfoxidation
•Reduction
•Hydrolysis
Phase II
•Conjugation
glucuronidation
sulfation glycine
acetylation
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 20/60
Cytochrome P450 Phase I Isoenzymes,
% Total and Substrate Examples
Isoenzymes%Substrate
CYP1A217Olanzapine, Theophylline
CYP2C9/1926Phenytoin, Warfarin
CYP2D62-4Codeine, Desipramine, Tramadol
CYP2E19-10Chlorzoxazone, Ethanol
CYP3A435-45Diazepam, Triazolam, Quinidine,
Methadone, Carbamazepine
www.drug-interactions.com
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 21/60
Inhibitors of Hepatic Cytochrome P450
2 A1 19/9C2 6D24 A3
Fluvoxamine AmiodaroneFluoxetineErythromycin
CimetidineFluconazoleParoxetine Azole
antifungalCiprofloxacinFluvastatinQuinidineNefazodone
FluoxetineRitonavir Clarithromycin
IsoniazidBupropionRitonavir
SertralineCimetidineCimetidine
Omeprazole Cimetidine
www.drug-interactions.com
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 22/60
Drugs That Interact with Theophylline
Inhibitors
•Cimetidine
•Propafenone
•Mexiletine
•Propranolol
•Erythromycin
•Ciprofloxacin
•Fluvoxamine
Drugs Aging. 2003;20:71-84
Inducers
•Barbiturates
•Phenytoin
•Smoking
•Rifampin
•Carbamazepine
JAPHA 2004;44:142-51
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 23/60
Drug-Drug Interactions With WarfarinInteracting DrugMechanism Anticoagulant Effect
AspirinPD
BarbituratePK
CimetidinePK
DipyridamolePD
FibratesPD
FluvoxaminePK
MacrolidesPKPhenytoinPK
QuinolonesPK
RifampinPK
SulfinpyrazonePK/PD
Thyroid hormonesPD TiclopidinePD
N Engl J Med. 2003; 14;349:675-83; JAPHA 2004;44:142-51
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 24/60
Clinically Significant
Drug-Drug Interactions with AEDs
Object DrugInteracting DrugOutcome
CarbamazepineDanazol CBZ
level
CarbamazepineDiltiazem CBZ level
CarbamazepineMacrolides
CBZ levelCarbamazepinePropoxyphene CBZ level
CarbamazepineVerapamil CBZ level
Phenytoin Amiodarone DPH level
PhenytoinCimetidine DPH level
PhenytoinFluoxetine DPH level
PhenytoinINH DPH level
PhenytoinOmeprazole DPH level
Neuropharmacology 2002;5:280-9
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 25/60
Inducers of Hepatic Cytochrome P450
2 A1 19/9C2 6D24 A3
SmokingRifampinNoneCarbamazepine
OmeprazolePhenobarbitalPhenytoin
PhenytoinPhenytoinPhenobarbital
Rifampin
St. John’s wort
www.drug-interactions.com
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 26/60
Selected Phenytoin
Induction Interactions
Object DrugInteracting DrugCYP
IsoenzymeInduced
MethadonePhenytoin3A4
QuinidinePhenytoin3A4
TheophyllinePhenytoin1A2
WarfarinPhenytoin2C9
Neuropharmacology 2002;5:280-9.
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 27/60
Selected Drugs Secreted
by Renal Tubules
Basic (cationic) Agents
• Amiodarone
•Cimetidine
•Digoxin•Procainamide
•Quinidine
•Ranitidine
•Trimethoprim
•Verapamil
Acidic (Anionic) Agents
•Cephalosporins
•Indomethacin
•Methotrexate•Penicillins
•Probenecid
•Salicylates
•Thiazides
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 28/60
Drug-Drug Interactions With Digoxin
Interacting DrugEffect on Levels
Amiodarone
Clarithromycin
Propafenone
Quinidine
Verapamil
Drug Saf. 2000;23:509-32; JAPHA 2004;44:142-51
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 29/60
Drug-Drug PD Interactions
Object DrugInteracting Drug (s)
ACE-IK+ & K+ sparing diuretics
Beta blockersVerapamil
DigoxinDiureticsMAOISSRI, Dextromethorphan,
Pseudoephedrine, Anorexiants
MeperidineMAOI
HydroxyineThioridazine
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 30/60
Drug- TCA PD Interactions
•Concurrent use with any other drugs with
antimuscarinic properties
•Concurrent MAOI
•Type I antiarrhythmics
•Clonidine
•Guanadrel
•Guanethidine
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 31/60
Drug-NSAID PD Interactions
Object DrugInteracting DrugOutcome
AntihypertensivesNSAIDs BP
CorticosteroidsNSAIDs risk of PUD
DiureticsNSAIDs diuretic effect
TriamtereneIndomethacin
K+
WarfarinNSAIDs
anticoagulanteffect
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 32/60
CNS Polypharmacy and Falls in
Elderly Persons
1
1.54
2.37
0
1
2
3
4
5
A
d j u s t e d o d d s r a t i o
0 1 >2
CNS - active medications (n)
Weiner D, et al. Gerontol 1998;44:217-21
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 33/60
Drug-Food/Nutrient Interactions
Drug Effect
Phenytoin ↓ Folate
Isoniazid ↓ Vit B6
Phenytoin ↓ Absorption with NG
feedings
Levodopa High protein meals effect
blood-brain transport
Captopril Altered taste sensation
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 34/60
Clinically Significant
Drug –St. John Wort Interactions
Object DrugOutcome
Antidepressantsserotonergic syndrome
Cyclosporine levels, transplant
rejectionDigoxin digoxin levels
Estrogenbreakthrough bleeding
Indinavir indinavir levels
Methadonewithdrawal sx’s
Tacrolimus levels
Theophylline theophylline levels
Warfarin INR CPT 2004;75:1-12
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 35/60
Other Clinically Significant Herb- Drug
Interactions
Object DrugInteracting DrugOutcome AnticonvulsantsWormwood seizure threshold
AnticonvulsantsGingko biloba seizure threshold
DigoxinHawthorne digoxin activity
Saquinavir Garlic saquinavir levels
WarfarinFeverfew risk of bleedingWarfarinGarlic risk of bleeding
WarfarinGinger risk of bleeding
WarfarinGinkgo risk of bleeding
WarfarinGinseng
anticoagulant Lancet 2000;355:134-8.
Clinically Important Drug Disease
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 36/60
Clinically Important Drug-Disease
Interactions Determined by Expert Panel
Consensus DrugDisease – AnticholinergicsBPH, constipation, dementia
– Antiarrhythmics (Type 1A)CHF (systolic dysfunction)
– AmphetaminesHTN, insomnia
– AspirinPUD
– Atypical antipsychoticsDM
–BarbituratesDepression –BenzodiazepinesCOPD,dementia, falls
–Beta-blockersCOPD, DM, syncope
–CCB 1st generationCHF (systolicdysfunction)
–ChlorpromazinePostural hypotension, seizures
–ClozapineSeizures –CorticosteroidsDM, PUD
–DecongestantsInsomnia
–DigoxinHeart block
Lindblad C, Hanlon J et al. (abstract) J Am Geriatr Soc 2004;52:S135
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 37/60
Clinically Important Drug-Disease
Interactions Determined by Expert Panel
Consensus DrugDisease –MetoclopramideParkinson’s disease
–NitrofurantoinChronic renal failure
–Non-aspirin NSAIDsCRF, CHF, HTN
–Non-aspirin, non-COX II NSAIDsPUD
–Opioid analgesicsBPH, constipation, dementia –Sedative/hypnoticsFalls
–Skeletal muscle relaxantsBPH
–SSRIsFalls
–TheophyllineInsomnia
–ThioridazinePostural hypotension,
seizures –ThorazineSeizures
–Tricyclic antidepressants Arrhythmias, BPH,constipation
dementia, falls, heart block
postural hypotension
–Typical antipsychoticsFalls
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 38/60
Learning Objectives
At the conclusion of this talk the participant should be able
to:
•List the 4 major types of drug interactions that can occur
in the elderly
•Discuss the epidemiology of the different types of drug
interactions in the elderly
•Implement strategies to prevent/manage drug
interactions in the elderly
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 39/60
Epidemiology of Drug-Drug or
Drug-Disease Interactions
•Incidence of potential drug-drug interactions ranges from 2-17% of all Rx's and up to 6-42% of elderly patients.
•Incidence of potentially clinically significant drug interactionsis low in the elderly (usually must involve narrow therapeuticrange drug and inhibitor/inducer of drug metabolism or renal
excretion) •There is evidence suggesting that adverse health outcomesassociated with drug-drug interactions is infrequent.
•Drug-disease interactions occur in 6.2-40% of elderlypatients
•Drug disease interactions may result in higher risk of adverse outcomes (e.g., decline in functional status and
increased health services use) due to alterations inhomeostatic mechanisms and diminished functional
reserve.
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 40/60
Drug Interactions Are Avoidable
Gosney et al. Lancet 1984;2:564
Previous
adverse
reactions
Contraindicated
drugs
Drug
interactions
Totals
Avoidable 7 57 67 131
Probably
avoidable
---- ---- 37 37
Uncertain ---- 3 29 32
Total 7 60 133 200
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 41/60
Strategies to Prevent/Manage
Drug Interactions
1. Encourage patients to report all prescription, over-
the- counter and complementary and alternativedrugs at every health care encounter.
2. Support the implementation of electronic prescribing and/or the use by patients of one pharmacy with
updated drug interaction software.
3. Work with pharmacists and be familiar with drug
interaction information sources4. Consider whether drug therapy is necessary
5. When adding a new drug to regimen, screen for potential drug-drug interactions.
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 42/60
Strategies to Prevent/Manage
Drug Interactions
6. When adding a new drug to regimen in a patient,
screen
for potential drug-disease interaction.
7. If drug interaction can not be avoided, adjust doses
and
or/dosage intervals for affected medication and monitor
the patient closely.
8. Carefully monitor other drug therapy when withdrawinga drug that can inhibit or induce hepatic metabolism.
9. Regularly review the need for chronic medications-
reduce polypharmacy
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 43/60
Interaksi farmakokinetik
makanan merubah proses absorbsi distribusi metabolisme
dan ekskresi obat sehingga kadar obat dalan plasma dan pada target
Sel menurun atau meningkat sampai ada efek toksik.
Interaksi farmakodinamik
makanan atau komponen makanan berinteraksi ditempat dimanaObat bekerja Misalnya di enzim, di reseptor dikanalion dan tempat lain
Yang secara tidak langsung meningkatkan ligand atau nerotrasmiter
Reseptor adrenergik cholinergikEnszim acetylcholine esterase
Na-K ATP ase
COx1 dan COX2
Kanalion Ca dan |Na
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 44/60
Warfarin (Coumadin)
The amount of Vitamin K in your body affects how
this drug works. It is best to eat the same amount
of Vitamin K every day. Vitamin K is present in
meats and green leafy vegetables (broccoli,
cabbage, collard greens, kale, lettuce & spinach).
Alfalfa sprouts, watercress, soy products, liver,
beef, pork contain significant amounts of Vitamin
K. Do not make large changes in the amount of these foods you eat every day while taking this
medicine.
Limit amount of alcohol to 1-2 drinks per day.
Vitamin E, Fever Few, Gingko Biloba, Don Quai,
ginger, garlic, Vitamin C and green tea may alsoproduce an enhanced anticoagulant effect with
Warfarin.
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 45/60
Warfarin* Common Name: Coumadin*
Cautions: Keep a steady level of vitamin K in your diet. Vitamin K foods
include green leafy vegetables (such as broccoli, cabbage, collard greens,
kale, lettuce, spinach), soybean oil, meats, dairy products, egg yolks and liver.
Do not change your diet or vitamin intake significantly without asking your
physician.Do not drink alcohol. Limit caffeine-containing foods and beverages
(chocolate, coffee, tea, colas) to one serving per day. Do not take oral,
vitamin-fortified diet beverages (such as Ensure or Boost) unless you are
already using them. Do not participate in weight reduction diets while on this
medication.
Avoid products with ginseng (such as Ginsana).Continue these precautions until your doctor or pharmacist says otherwise.
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 46/60
Grapefruit juice can actually inhibit the body's absorption of
certain drugs including:
Vinblastine (for combating cancer)
Cyclosporine (for supressing organ rejection following
transplant)
Losartan (for controlling high blood pressure)
Digoxin (for treating congestive heart failure)
Fexofenadine (for alleviating allergy symptoms)
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 47/60
Pharmacokinetics
•Absorption: Not highly impacted
by aging
•Variable changes in first pass
metabolism due to variable
decline in hepatic blood flow
(elders may have less first pass
effect than younger people, butextremely difficult to predict)
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 48/60
Pharmacokinetics and the
Liver •Acetylation and conjugation do not
change appreciably with age
•Oxidative metabolism throughcytochrome P450 system does
decrease with aging, resulting in a
decresed clearance of drugs
•Hepatic blood flow extremely
variable
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 49/60
Pharmacodynamics:
What the Drug does to the Body
•Some effects are increased –Alcohol causes increase is
drowsiness and lateral sway in older people than younger people at same
serum levels
–Fentanyl, diazepam, morphine,
theophylline
•Some effects are decreased –Diminished HR response to
isoproterenol and beta -blockers
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 50/60
Drug-Drug Interactions
•Common cause of ADEs in elderly•Almost countless – good role for
pharmacist and computer or on-line
programs•Some common examples
–Statins and erythromycin and other antibiotics
–TCAs and clonidine or type 1Anti-arrythmics
–Warfarin and multiple drugs
– ACE inhibitors increase hypoglycemic effect of sulfonylureas
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 51/60
Drug-disease Interactions
•Patient with PD have increased risk of druginduced confusion
•NSAIA (and COX-2’s) s can exacerbate
CHF•Urinary retention in BPH patients on
decongestants or anticholinergics
•Constipation worsened by calcium,
ahticholinergics, calcium channel blockers•Neuroleptics and quinolones lower seizure
thresholds
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 52/60
Drug-Food Interactions
•Interactions between drugs and food
–warfarin and Vitamin K containing foods
(remember green tea, as well)
–Phenytoin & vitamin D metabolism –Methotrexate and folate metabolism
•Drug impact on appetite
–Digoxin may cause anorexia
– ACE inhibitors may alter taste
Herbals and
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 53/60
Herbals and
Supplements:Potential
interactions with Rx Drugs•SAMe may increase homocysteine levels
•St. John’s wort and Oral contraceptives
•Ginkgo may increase anticoagulant
effects of ASA, warfarin, NSAIAs,
ticlopidine, and may interact with MAOIs
•Bottom line: Try to know what your
patient is taking, and ask in a
nonjudgmental way
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 54/60
High Risk Situations
•Patient seeing multiple providers
•Patient on multiple drugs
•Patient lives alone and/or has
cognitive impairment
•Discharge from hospital or any
change in venue
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 55/60
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 56/60
Ginkgo (Ginkgo bi loba ), particularly a standardized
extract known as EGb 761, appears to produceimprovements in awareness, judgment, and social function
in people with Alzheimer's disease and dementia. In a
year-long study of 309 people with Alzheimer's disease,
those taking EGb 761 consistently improved while those
on placebo worsened.
Kava kava (Piper methyst icum ) has become popular as
a treatment for anxiety, but recent reports have traced liver
damage to enough people who have used kava that the
U.S. FDA has issued a warning regarding its use and other countries, such as Germany and Canada, have taken kava
off of the market
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 57/60
St. John's wort (Hyper icum perforatum ) is well known
for its antidepressant effects, and an analysis of 27 studiesinvolving more than 2,000 people confirmed that the herb
is an effective treatment for mild to moderate depression.
Valerian (Valeriana o ff icinal is ) has had a long tradition as
a sleep-inducing agent, with the added benefit of producing no hangover feeling the next day.
Echinacea preparations (from Echinacea pu rpu rea and
other Echinacea species) may bolster immunity. In a
study of 160 volunteers with flu-like symptoms, echinacea
extract reduced both the frequency and severity of cold
symptoms.
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 58/60
Is there anything I should watch out for?
Used correctly, many herbs are considered safer than
conventional medications, but because they are
unregulated, herbal products are often mislabeled and may
contain undeclared additives and adulterants.
Some herbs are associated with allergic reactions or
interact with conventional drugs.
Self-prescribing herbal products will increase your risk, so it
is important to consult your doctor and an herbalist before
taking herbal medicines..
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 59/60
Some examples of adverse reactions from certain popular
herbs are described below
St. John's wort causes sensitivity to the sun's ultraviolet
rays, and may cause an allergic reaction, stomach upset,fatigue, and restlessness. Studies show that St. John's wort
also interferes with the effectiveness of many drugs,
including warfarin (a blood thinner), protease inhibitors for
HIV, possibly birth control pills, and many other medications. In addition, St. John's wort must not be taken
with anti-depressant medication.
The Food and Drug Administration (FDA) has issued a
public health advisory concerning many of these
interactions.
Kava kava and echinacea have both been linked to liver
toxicity. Again, kava has been taken off the market in
several countries because of the liver toxicity.
7/16/2019 DRUG_–_FOOD_-_HERBA_dd
http://slidepdf.com/reader/full/drugfood-herbadd 60/60
Valerian may cause oversedation, and in some people itmay even have the unexpected effect of overstimulating
instead of sedating.
Feverfew (Tanacetum parthenium) may cause agitation.
Bleeding time may be altered with the use of garlic,ginkgo, feverfew, ginger (Zingiber officinale) and ginseng