Term
| Clonidine (Catapres) and guanfacine (Tenex) are part of what drug group? |
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Definition
| α2-adrenergic receptor agonists |
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Term
| What are the four central therapeutic indications for clonidine (or guanfacine) in psychiatric practice? |
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Definition
ADHD
Opioid withdrawal
Tourette's disorder
Agitation in PTSD |
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Term
| What is the mechanism of action for clonidine (or guanfacine)? |
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Definition
| Stimulation of presynaptic α2-adrenergic receptors reduces the firing rate of noradrenergic neurons. Net result: lower plasma concentrations of norepinephrine. |
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Term
| Clonidine and guanfacine are uselful in the treatment of withdrawal symptoms from which 4 substances? |
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Definition
Opioids - objective signs only, not subjective feelings
Alcohol
Benzodiazepines
Nicotine
For the last three, helpful also with reducing anxiety |
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Term
| Can clonidine or guanfacine be combined with methylphenidate (Ritalin)? |
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Definition
Yes. A few cases have been reported of sudden death of children taking clonidine with Ritalin, but no conclusive evidence has been found to show that these medications contributed to the deaths.
Periodic ECGs are warranted. |
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Term
| A clonidine patch can help reduce which side-effects caused by a common antipsychotic? |
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Definition
| It can reduce the hypersalivation and dysphagia caused by clozapine (Clozaril). |
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Term
| What are the 7 common adverse effects associated with clonidine? |
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Definition
Dry mouth and eyes
Fatigue
Sedation
Dizziness
Nausea
↓BP
Constipation
These result in discontinuation in 10% of patients |
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Term
| Can clonidine cause sexual dysfunction? |
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Definition
|
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Term
| What are the absolute CI to clonidine (and guanfacine) therapy? |
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Definition
BP<90/60
Cardiac arrhythmias (especially bradycardia) |
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Term
| What are the 3 uncommon CNS adverse effects of clonidine? |
|
Definition
Insomnia
Anxiety
Depression |
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Term
| What 3 rare CNS adverse effects are associated with clonidine? |
|
Definition
Hallucinations
Vivid dreaming
Nightmares |
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Term
| Can clonidine cause sedation? |
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Definition
| Yes. Tolerance to this side effect usually does not develop. |
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Term
| What does an overdose of clonidine look like? |
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Definition
| Presents as an opioid overdose. May present as coma with constricted pupils, or as ↓BP, ↓P and ↓RR. |
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Term
| What are the 6 relative CI to clonidine therapy? |
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Definition
Heart disease
Vascular disease
Renal disease
Raynaud's phenomenon
History of depression
Pregnancy or breastfeeding |
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Term
| How does the response to clonidine change among different age groups? |
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Definition
Elderly people are more sensitive to the drug
Children are not affected differently |
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Term
| What can happen on abrupt discontinuation of clonidine? How soon do these symptoms occur? |
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Definition
Abrupt discontinuation may cause anxiety, restlessness, perspiration, tremor, abdominal pain, palpitations, headache and sharp rise in BP.
These symptoms may appear ~20 hrs after the last dose of clonidine, and thus may appear after skipping 1-2 doses. |
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Term
| What 5 categories of drug interactions are significant with clonidine? |
|
Definition
1. TCAs - reduce the hypotensive effect of clonidine
2. Clonidine and guanfacine may enhance the CNS-depressive effects of barbiturates, alcohol, sedative-hypnotics, and trazodone
3. Synergistic effect with other anti-hypertensives
4. Blocked by yohimbine (Yocon)
5. β-blockers - enhance the rebound effect when clonidine/guanfacine is discontinued |
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