NPP 3 (drug interactions) Flashcards
1
Q
What are pharmacodynamic drug-drug interactions?
A
Interactions involving drugs with similar/identical target actions resulting in additive or potentiating actions
These can often be predicted based on known actions.
2
Q
What are pharmacokinetic drug-drug interactions?
A
Interactions involving the alteration of absorption, distribution, metabolism, or excretion of one drug by another
These interactions are extensive and often unpredictable.
3
Q
Why are drug-drug interactions of clinical importance?
A
They often involve drugs with narrow therapeutic indices and occur in patients with co-morbidity or requirements for multiple drug usage
Examples include tricyclic antidepressants, lithium, phenytoin, and warfarin.
4
Q
What is the ‘cheese’ reaction?
A
A hypertensive crisis associated with MAOIs due to the consumption of tyramine-rich foods
This reaction occurs when pressor amines enter systemic circulation.
5
Q
What are the two types of monoamine oxidase (MAO)?
A
MAOA and MAOB
These isoenzymes provide a barrier to the passage of pressor amines into systemic circulation.
6
Q
What can cause hypertensive crises in patients taking MAOIs?
A
Increased release of noradrenaline and/or adrenaline, leading to arteriolar constriction and hypertension
Symptoms include anxiety, pallor, nausea, sweating, headache, and palpitations.
7
Q
What are the symptoms of a hypertensive crisis?
A
- Anxiety
- Pallor
- Nausea
- Sweating
- Headache
- Palpitations
Severe cases can lead to CVA, myocardial ischemia, or death.
8
Q
What characterizes Serotonin Syndrome?
A
Neuromuscular hyperactivity, autonomic hyperactivity, and altered mental state
It can be life-threatening.
9
Q
What are some symptoms of Serotonin Syndrome?
A
- Tremor
- Clonus
- Myoclonus
- Hyperreflexia
- Pyramidal rigidity
- Diaphoresis
- Fever
- Tachycardia
- Tachypnoea
- Mydriasis
- Agitation
- Confusion
- Coma
These symptoms are indicative of excessive serotonin levels.
10
Q
What can lead to excessive synaptic serotonin concentration?
A
- Reuptake inhibition
- Presynaptic release
- MAO inhibition
This can result from various drug interactions.
11
Q
Name some drugs that can cause Serotonin Syndrome.
A
- Traditional MAOIs (e.g., tranylcypromine)
- SSRIs (e.g., fluoxetine, clomipramine)
- MAOI + SSRI combinations
- Moclobemide + SSRIs
- Moclobemide + powerful releasers (e.g., amphetamines, MDMA)
These combinations can significantly increase serotonin levels.
12
Q
What is the Cytochrome P450 system responsible for?
A
Steroid synthesis and phase 1 metabolism of endogenous compounds and xenobiotics
It involves 57 encoding genes and plays a crucial role in drug metabolism.
13
Q
What are the two main types of metabolic actions in the Cytochrome P450 system?
A
- Mitochondrial - steroid synthesis
- Microsomal - oxidative metabolism
These processes are widely distributed in the liver, gut wall, and brain.
14
Q
What does ‘toxidrome’ refer to in pharmacology?
A
A toxic syndrome resulting from drug interactions or overdoses
It is often used to describe specific toxicological presentations.
15
Q
Fill in the blank: The Cytochrome P450 system is characterized by ‘CY’ for _______.
A
cytochrome
‘P450’ refers to its spectrophotometry characteristic.
16
Q
What is the primary function of mitochondrial enzymes?
A
Steroid synthesis
Located in the inner membrane of mitochondria
17
Q
What is the primary function of microsomal enzymes?
A
Oxidative metabolism
Found in the endoplasmic reticulum and widely distributed in the liver, gut wall, and brain
18
Q
What does ‘CY’ in the Cytochrome P450 System stand for?
A
‘Cytochrome’
It refers to a haemoprotein respiratory pigment
19
Q
What does ‘P450’ indicate in the Cytochrome P450 System?
A
Spectrophotometry characteristic (peak at wavelength of absorption maximum)
20
Q
What is the naming convention for Cytochrome P450 enzymes?
A
CYP followed by a number (gene family), a letter (gene subfamily), and a number (gene number)
Example: CYP2D6
21
Q
Which major isoform of interest in psychopharmacology is represented by CYP1A2?
A
CYP1A2
22
Q
Which major isoforms of interest in psychopharmacology are represented by CYP2D6?
A
CYP2D6
23
Q
Which major isoforms of interest in psychopharmacology are represented by CYP2C9 and CYP2C19?
A
CYP2C9 & CYP2C19
24
Q
Which major isoforms of interest in psychopharmacology are represented by CYP3A3/4?
A
CYP3A3/4
25
What is the significance of the Cytochrome P450 system's distribution?
It makes a major contribution to phase 1 metabolism, utilized by many psychotropics
26
What is unique about CYP2D6 in terms of drug metabolism?
It is resistant to induction
27
What does 'intermediate' metabolizers refer to?
Functioning alleles at any locus, representing the 'majority' population effect
28
What are 'ultra-rapid' metabolizers characterized by?
Extra wild-type alleles of normal metabolic activity
29
What characterizes 'poor' metabolizers in the context of genetic polymorphisms?
Mutant alleles leading to decreased or absent metabolic activity
30
What is the frequency of CYP2D6 polymorphisms in Caucasians?
5 - 10%
31
What is the frequency of CYP2C19 polymorphisms in Caucasians?
3 - 5%
32
What is the significance of 'responsivity' in pharmacokinetics?
It refers to genetically determined baseline action
33
What does induction in the context of drug interactions lead to?
Enhanced activity and increased removal of other drugs using that isoform
34
What is the effect of inhibition on metabolic activity?
Diminished activity and decreased removal of other drugs using that isoform
35
What is the implication of drug-drug interactions in psychiatry?
They are significant and can affect various drug classes
36
Which drug classes are particularly affected by drug-drug interactions?
* Antidepressants
* Antipsychotics
* Sedative/hypnotics
* Mood stabilizers
* Central stimulants
* Cognitive enhancers
37
What is a significant concern with sedative/hypnotics in drug interactions?
Potentiated action via GABAA receptor
38
What percentage of males and females use alcohol alongside benzodiazepines?
88% males / 79% females
39
What is one of the leading causes of injury death in the United States since 2008?
Self-poisoning
40
What is the death rate from opioid analgesics in the United States from 2000-2010?
Increased 5 times in women, 3 times in men
41
What are common examples of opioid analgesics that can interact with other drugs?
* Methadone
* Heroin
* Morphine
* Codeine
* Oxycodone
42
What is the risk associated with combining opioids and benzodiazepines?
Increased risk of respiratory depression
43
What is the significance of drug-drug interactions in psychiatry?
Drug-drug interactions can lead to serious consequences, including increased mortality rates.
44
Which sedative/hypnotics are always significant in drug-drug interactions?
Sedative/hypnotics such as benzodiazepines and barbiturates are always significant.
45
What is the death rate increase for oxycodone in the United States over 5 years?
Death rate up 264% in 5 years.
46
What percentage of deaths in the UK from dihydrocodeine occurred between 1997-2007?
Approximately 650 deaths.
47
What are some common combinations that lead to increased risk?
* Methadone: 23%
* Alcohol: 27%
* Heroin: 50%
* Sedative hypnotics: 51%
48
What are potential effects of combining benzodiazepines with other substances?
Potentiated action via GABAA and respiratory depression.
49
What are MAOIs and why are they significant in drug interactions?
MAOIs are monoamine oxidase inhibitors that can cause hypertensive crises and serotonin syndrome.
50
What is the 'cheese reaction' associated with MAOIs?
Hypertensive crises due to foods high in pressor amines.
51
What is serotonin syndrome and its potential severity?
A potentially fatal condition caused by excess serotonin.
52
Which antidepressants are considered to have significant drug-drug interactions?
* MAOIs
* SSRIs
* TCAs
53
What can SSRIs combined with NSAIDs lead to?
Bleeding diathesis, especially in the upper GI tract.
54
What are the adjusted odds ratios for NSAID + SSRI interactions?
4.8 (2.8-8.3)
55
What role do antiplatelets play in drug interactions with SSRIs?
They can increase the risk of bleeding when used with SSRIs.
56
What is the risk of lithium toxicity when combined with diuretics?
Diuretics can reduce lithium clearance by up to 40%.
57
What are common side effects of combining sedatives with antidepressants?
* Sedation
* Constipation/retention
* Visual disturbance
* Confusion
58
What is the concern with clozapine in drug interactions?
Risk of agranulocytosis.
59
What is QTc prolongation and which drugs are associated with it?
A condition that can be exacerbated by antipsychotics and certain antidepressants.
60
Fill in the blank: MAOIs can lead to _______ crises.
hypertensive
61
True or False: All antipsychotics have clinically significant drug-drug interactions.
False
62
What is the mechanism behind the effects of antidepressants on platelet competence?
SSRIs can affect platelet function, leading to bleeding risks.
63
Which enzyme systems are involved in pharmacokinetic drug-drug interactions?
* CYP2C19
* CYP2D6
* CYP1A2
64
What is the potential effect of disulfiram when combined with alcohol?
Accumulation of acetaldehyde leading to adverse reactions.
65
What is the clinical significance of combining antimuscarinics with prokinetics?
Inhibition of prokinetic actions.
66
What percentage of cases indicated an interaction with NSAIDs and TCAs?
3.1 (1.9-5.1)
67
What is the primary mechanism by which N-demethylation occurs?
A metabolic process where a methyl group is removed from a nitrogen atom in a molecule.
68
Name a selective serotonin reuptake inhibitor (SSRI).
(Es)citalopram
69
What is O-desmethylvenlafaxine a metabolite of?
Venlafaxine
70
What is the primary function of Mirtazapine?
An antidepressant medication
71
Which antipsychotic is known for its use in treatment-resistant schizophrenia?
Clozapine
72
Name a common benzodiazepine used for anxiety.
Diazepam
73
Fill in the blank: _______ is a drug used to treat Alzheimer's disease.
Donepezil
74
What class of drugs does Carbamazepine belong to?
Anticonvulsants
75
True or False: Fluoxetine is a tricyclic antidepressant.
False
76
What type of drug is Quetiapine?
Antipsychotic
77
List two major CYP450 enzymes involved in drug metabolism.
* 2C19
* 2D6
78
What is the effect of St John's Wort on drug metabolism?
It acts as an inducer.
79
What is the major isomer of Warfarin?
S isomer
80
Fill in the blank: _______ is used as a treatment for opioid overdose.
Naloxone
81
What are the two primary metabolic processes for Diazepam?
* N-methylation
* Hydroxylation
82
Name a drug that is a substrate for CYP2D6.
Codeine
83
What is the role of Protease inhibitors in drug interactions?
They can inhibit drug metabolism.
84
True or False: Grapefruit juice can inhibit CYP3A4.
True
85
What type of drug is Haloperidol?
Antipsychotic
86
List three common non-steroidal anti-inflammatory drugs (NSAIDs).
* Ibuprofen
* Naproxen
* Diclofenac
87
What is the primary action of Donepezil?
Inhibits acetylcholinesterase
88
Fill in the blank: _______ is a drug that can induce CYP2C9.
Rifampicin
89
What are the effects of Barbiturates on drug metabolism?
They act as inducers.
90
Name a common side effect of SSRIs.
Sexual dysfunction
91
What type of drug is Aripiprazole?
Atypical antipsychotic
92
List the two main types of drug-drug interactions.
* Pharmacokinetic
* Pharmacodynamic
93
True or False: Fluoxetine can be used as a treatment for bulimia nervosa.
True
94
What is the significance of CYP2D6 in pharmacogenomics?
It affects drug metabolism and individual responses to medications.
95
Fill in the blank: _______ is a common treatment for ADHD.
Atomoxetine
96
What is the role of Fluvoxamine in pharmacokinetic drug-drug interactions?
Fluvoxamine is a strong inhibitor of CYP1A2 and CYP2D6 enzymes.
97
Name three drugs metabolized by CYP1A2.
* Clozapine
* Olanzapine
* Theophylline
98
What type of drug is Mirtazapine?
Mirtazapine is a tertiary amine tricyclic antidepressant.
99
Fill in the blank: _______ is a strong inhibitor of CYP1A2.
Fluvoxamine
100
List two common inducers of CYP1A2.
* Cigarettes
* Carbamazepine
101
What effect do strong inhibitors have on drug metabolism?
They slow down the metabolism of drugs.
102
True or False: Caffeine is a strong inhibitor of CYP1A2.
False
103
What is the consequence of combining clozapine with fluvoxamine?
Increased clozapine levels due to inhibition of its metabolism.
104
Name a drug that is an inducer of CYP2D6.
Carbamazepine
105
Fill in the blank: _______ is a weak inhibitor of CYP2D6.
Bupropion
106
What type of drugs are at higher risk of QTc prolongation?
Drugs that inhibit their metabolism.
107
List three drugs that can inhibit CYP2D6.
* Paroxetine
* Fluoxetine
* Ritonavir
108
True or False: Codeine is metabolized to morphine by CYP2D6.
True
109
What is the primary concern with using SSRIs alongside sedative properties drugs?
Increased risk of sedation and potential respiratory depression.
110
Fill in the blank: _______ is a drug that has potential interactions with warfarin.
Sertraline
111
Name two drugs that are strong inducers of CYP2C9.
* St John's Wort
* Ginkgo biloba
112
What is the major pathway for warfarin metabolism?
CYP2C9 (major 'S' isomer)
113
List three drugs that should be avoided in patients on warfarin.
* Fluoxetine
* Paroxetine
* Valproate
114
True or False: Grapefruit juice is a known inhibitor of CYP1A2.
True
115
What is the effect of barbiturates on drug metabolism?
They act as strong inducers of various CYP enzymes.
116
Fill in the blank: _______ is a type of drug that can lead to QTc prolongation when combined with certain antipsychotics.
Sertindole
117
What is the major isomer of warfarin?
S isomer
118
Which drug is a strong inhibitor of CYP450 enzymes?
Fluvoxamine
119
Name two drugs that are strong inducers of CYP450 enzymes.
* Carbamazepine
* Rifampicin
120
Which herbal product is known to induce CYP450 enzymes?
St John’s Wort
121
What is the potential effect of St John’s Wort on warfarin?
May affect INR stability
122
Which NSAIDs should be avoided in patients on valproate?
* Celecoxib
* Diclofenac
* Ibuprofen
* Indomethacin
* Naproxen
123
Fill in the blank: The use of _______ in patients on valproate is cautioned.
NSAIDs
124
Which pathway is significant for the metabolism of tertiary amine tricyclics?
N-demethylation
125
Name a drug that is a strong inhibitor of CYP2C19.
Fluvoxamine
126
True or False: Interactions with CYP2C19 are rarely significant for most psychotropics.
True
127
Which drug is known to increase the levels of clozapine?
SSRIs (including St John’s Wort)
128
Which two compounds should NOT be co-administered due to the risk of agranulocytosis?
* Clozapine
* Carbamazepine
129
What is the effect of diazepam when combined with proton pump inhibitors?
Potential for increased sedation
130
Fill in the blank: _______ is a minor metabolic pathway for most psychotropics.
CYP2C19
131
Name a drug that is a weak inducer of CYP3A4.
Modafinil
132
What should be avoided in patients taking warfarin?
Strong inhibitors
133
List three drugs that are known to be strong inducers.
* Carbamazepine
* Phenobarbital
* Phenytoin
134
What is the significance of the 3A3/4 pathway in pharmacokinetics?
Metabolizes many psychotropic drugs
135
Fill in the blank: The less active isomer of warfarin is _______.
R-warfarin
136
What potential interaction is noted with moclobemide?
Increased action on R-warfarin
137
Which drug class includes drugs like atorvastatin and simvastatin?
Statins
138
True or False: The combination of diazepam and H2 antagonists is always clinically significant.
False
139
What is the role of chloramphenicol in drug interactions?
Strong inhibitor
140
Name a drug that can cause unstable INR when co-administered with antidepressants.
Warfarin
141
What is a common effect of combining opioids with certain psychotropic medications?
Increased sedation
142
Fill in the blank: _______ is a common pathway for the metabolism of diazepam.
N-methylation & hydroxylation
143
Which drug is a weak inhibitor of CYP3A4?
Dexamethasone
144
Name a drug that is contraindicated with clozapine due to agranulocytosis risk.
Carbamazepine
145
What is Hyperforin?
A compound found in St John’s Wort
## Footnote
Hyperforin is known for its potential antidepressant effects.
146
What is Trazodone primarily used for?
An antidepressant medication
## Footnote
Trazodone is often used to treat major depressive disorder.
147
Name a common pharmacokinetic interaction involving SSRIs.
Clozapine levels may be increased by co-administration of certain SSRIs
## Footnote
This includes SSRIs like fluoxetine and sertraline.
148
What are Tertiary amine tricyclics known for?
They undergo N-demethylation
## Footnote
This metabolic process affects their pharmacokinetics.
149
What is the role of CYP3A4 in drug metabolism?
Metabolizes a wide range of drugs, including many psychotropics
## Footnote
This pathway is significant for drug-drug interactions.
150
True or False: St John’s Wort is a strong inducer of CYP3A4.
True
## Footnote
It can significantly affect the metabolism of various medications.
151
List some examples of strong inducers of drug metabolism.
* Carbamazepine
* Rifampicin
* Phenobarbital
* Phenytoin
* Dexamethasone
## Footnote
These drugs can lower the plasma levels of co-administered medications.
152
What can result from the co-administration of clozapine and carbamazepine?
Increased risk of agranulocytosis
## Footnote
Both drugs have high risks of this serious side effect.
153
Fill in the blank: _______ is a triazole antifungal that is a potent inhibitor of CYP3A4.
[Ketoconazole]
## Footnote
It can significantly increase the blood levels of certain psychotropics.
154
What is the effect of macrolide antibiotics on drug metabolism?
They act as inhibitors
## Footnote
Examples include clarithromycin and erythromycin.
155
Which psychotropic medications are contraindicated with sertindole?
* Pimozide
* Certain triazole antifungals
## Footnote
This is due to the risk of serious cardiac effects.
156
What is the consequence of using SSRIs with immunosuppressants?
May contribute to instability in drug levels
## Footnote
This can affect the efficacy of immunosuppressive therapy.
157
Which medication is known for its use in the treatment of Alzheimer's disease?
Donepezil
## Footnote
Donepezil is an acetylcholinesterase inhibitor.
158
What is the significance of the 2D6 enzyme in psychiatry?
Metabolizes several psychotropic drugs
## Footnote
This includes tricyclics and some antipsychotics.
159
True or False: Grapefruit juice is an inhibitor of drug metabolism.
True
## Footnote
Specifically, bergamottin in grapefruit juice affects CYP3A4.
160
Fill in the blank: _______ is a common opioid analgesic that can interact with psychotropic medications.
[Methadone]
## Footnote
Methadone is used for pain management and opioid dependence.
161
What are some examples of weak inhibitors of CYP3A4?
* Citalopram
* Fluoxetine
* Dexamethasone
## Footnote
These medications have a lesser impact on drug metabolism compared to strong inhibitors.
162
What effect do protease inhibitors have on drug metabolism?
They are strong inhibitors of CYP3A4
## Footnote
Examples include ritonavir and saquinavir.
163
Name a medication that undergoes N-oxide-galantamine metabolism.
Galantamine
## Footnote
It is also used in the treatment of Alzheimer's disease.
164
What interaction occurs with the use of St John’s Wort and certain SSRIs?
May lead to increased clozapine levels
## Footnote
This interaction is significant due to the risk of side effects.
165
What is the primary concern when combining methadone with other medications?
Increased blood levels can be fatal
## Footnote
This highlights the importance of monitoring in polypharmacy.
166
Fill in the blank: _______ is a medication that can inhibit CYP2D6 and affect the metabolism of tricyclics.
[Fluoxetine]
## Footnote
Fluoxetine is an SSRI with multiple drug interactions.
167
What is Tramadol?
A medication used to treat moderate to severe pain
## Footnote
Tramadol is an opioid analgesic.
168
What is Dihydrocodeine?
An opioid used to relieve pain and as a cough suppressant
## Footnote
Dihydrocodeine is often used for moderate pain.
169
What is Dextromethorphan?
A cough suppressant found in many over-the-counter cold medications
## Footnote
Dextromethorphan is not an opioid.
170
What is the function of Diphenhydramine?
An antihistamine used to relieve allergy symptoms and as a sleep aid
## Footnote
It is also known for its sedative properties.
171
What is Promethazine?
An antihistamine used to treat allergies, motion sickness, and nausea
## Footnote
Promethazine is also used as a sedative.
172
What does MDMA stand for?
3,4-methylenedioxymethamphetamine
## Footnote
MDMA is commonly known as 'ecstasy'.
173
What are Class 1 antiarrhythmics?
Drugs that are used to treat arrhythmias by blocking sodium channels
## Footnote
Examples include Quinidine and Flecainide.
174
What is Metoclopramide used for?
To treat nausea and gastroparesis
## Footnote
It works by increasing the movements or contractions of the stomach and intestines.
175
What is Tamoxifen?
A medication used to prevent and treat breast cancer
## Footnote
Tamoxifen is a selective estrogen receptor modulator (SERM).
176
What class of drugs does Quinidine belong to?
Class 1 antiarrhythmics
## Footnote
Quinidine is primarily used to treat certain types of irregular heartbeat.
177
What is Paroxetine?
An SSRI antidepressant used to treat depression, anxiety disorders, and OCD
## Footnote
Paroxetine is known for its potential side effects.
178
What is Bupropion?
An antidepressant that is also used for smoking cessation
## Footnote
Bupropion is unique as it does not typically cause weight gain.
179
What is Fluoxetine?
An SSRI used to treat depression, OCD, and panic disorder
## Footnote
Fluoxetine is known for its long half-life.
180
What is Pimozide?
An antipsychotic used primarily to treat Tourette syndrome
## Footnote
Pimozide can also be used for severe behavioral problems.
181
What is Ritonavir?
An antiretroviral medication used to treat HIV
## Footnote
Ritonavir is also known for its role as a booster for other protease inhibitors.
182
What is Norfluoxetine?
The active metabolite of Fluoxetine
## Footnote
Norfluoxetine contributes to the therapeutic effects of Fluoxetine.
183
What is Cannabis?
A plant used for recreational, medicinal, and industrial purposes
## Footnote
Cannabis contains compounds called cannabinoids.
184
What is Sertraline?
An SSRI used to treat depression, anxiety, and PTSD
## Footnote
Sertraline is often prescribed for its efficacy and safety profile.
185
What is Desmethylsertraline?
The active metabolite of Sertraline
## Footnote
It plays a role in the drug's pharmacological activity.
186
What is Fluvoxamine?
An SSRI primarily used to treat OCD and anxiety disorders
## Footnote
Fluvoxamine has a unique profile among SSRIs.
187
What is Venlafaxine?
An SNRI used to treat major depressive disorder and anxiety disorders
## Footnote
Venlafaxine can cause dose-dependent increases in blood pressure.
188
What is Duloxetine?
An SNRI used to treat major depressive disorder and generalized anxiety disorder
## Footnote
Duloxetine is also indicated for neuropathic pain.
189
What is Moclobamide?
A reversible inhibitor of monoamine oxidase A (RIMA) used as an antidepressant
## Footnote
It is associated with fewer dietary restrictions than traditional MAOIs.
190
What is St John's Wort?
A herbal remedy used for mild to moderate depression
## Footnote
St John's Wort can interact with various medications.
191
What are H1 antagonists?
Antihistamines that block H1 receptors to alleviate allergy symptoms
## Footnote
Examples include Diphenhydramine and Chlorpheniramine.
192
What is Haloperidol?
An antipsychotic used to treat schizophrenia and acute psychosis
## Footnote
Haloperidol can cause extrapyramidal side effects.
193
What is Perphenazine?
An antipsychotic used to treat schizophrenia and severe nausea
## Footnote
Perphenazine is a typical antipsychotic.
194
What is Methadone?
An opioid used for pain management and as part of drug addiction detox programs
## Footnote
Methadone has a long half-life.
195
What is Erythromycin?
An antibiotic used to treat various bacterial infections
## Footnote
Erythromycin can interact with many drugs.
196
What is Ketoconazole?
An antifungal medication used to treat fungal infections
## Footnote
Ketoconazole is also a potent inhibitor of CYP enzymes.
197
What is Reboxetine?
An antidepressant that acts as a norepinephrine reuptake inhibitor
## Footnote
Reboxetine has a different mechanism than SSRIs.
198
What is Cocaine?
A powerful stimulant drug that can lead to addiction
## Footnote
Cocaine has significant effects on the central nervous system.
199
What are the effects of strong inhibitors of CYP 2D6?
They can significantly alter the metabolism of drugs processed by this enzyme
## Footnote
Examples include Fluoxetine and Paroxetine.
200
What are the general risks of pharmacokinetic drug-drug interactions?
They can lead to altered drug levels, reduced efficacy, or increased toxicity
## Footnote
These interactions can occur with prescribed and illicit drugs.
201
True or False: Pharmacodynamic interactions are generally easier to predict than pharmacokinetic interactions.
True
## Footnote
Pharmacodynamic interactions can often be foreseen based on known pharmacology.
202
What are the potential dangers of multiple sedative psychotropics?
They can cause respiratory depression and increase the risk of death
## Footnote
This risk is especially high when multiple mechanisms are involved.
203
Fill in the blank: Many psychotropic compounds are _________.
sedative
## Footnote
Sedative properties can lead to dangerous interactions.
204
What is the significance of Leah Betts in the context of drug interactions?
Her case highlighted the dangers of MDMA and its interactions with other substances
## Footnote
Leah Betts died in 1995 after taking MDMA.
205
What effect does caffeine have on MDMA toxicity?
Caffeine can seriously increase the toxicity of MDMA
## Footnote
This is particularly evident at doses of 5 - 20 mg.
206
What is the mechanism suggested for the increased toxicity of MDMA when combined with caffeine?
Enhanced dopaminergic action and anti-adenosine receptor activity
## Footnote
This combination can lead to lethality.
207
What is the average adult consumption of caffeine?
50 - 150 mg/day
## Footnote
This amount can influence the effects of MDMA.
