MEDICATIONS

It takes five half-lives of a medication to achieve steady-state levels in the body, so the correct answer is 120 hours.

The half-life is the time needed to clear 50% of the medication from the system. The steady-state is the point at which the amount of drug eliminated between doses is approximately equal to the dose administered.

Lithium is the gold standard for treating bipolar I disorder and manic episodes.

·         Labs needed before starting lithium are:

o   Serum creatinine

o   BUN

o   Electrolytes

o   Thyroid studies

o   Urinalysis

·         95% of lithium is excreted through the kidneys, so check kidney function.

·         Lithium inhibits the synthesis of thyroid hormone

Baseline lithium tests include thyroid panel, BUN/Creat, and a pregnancy test. It also includes EKG testing for patients over 50 years of age.

Can cause the heart defect known as Ebstein’s anomaly if given to a pregnant woman.

Therapeutic lithium levels are 0.8-1.2.

Normal BUN level: 6-24

Normal GFR level: 90-120

Normal creatinine level: < 1.5

Can cause leukocytosis (increased WBCs)

Overdose symptoms may not be seen for up to 48 hours

Lithium can cause polyuria and polydipsia because it blocks ADH

Lithium can increase calcium levels.

Lithium overdose symptoms: diarrhea, vomiting, stomach pains, tremors, fatigue

When lithium is first started, it may cause persistent fine hand tremor, polyuria, and mild thirst.

Nausea and vomiting from lithium are temporary and usually subside in a few days.

Ibuprofen increases plasma levels of lithium, which can result in lithium toxicity. Symptoms of lithium toxicity are sedation, vomiting, diarrhea, and tremor.

Lithium can cause T-wave flattening or inversion on an ECG.

Both lamotrigine and lithium can delay onset of mood-related episodes.

Lamotrigine, but not lithium, is superior to placebo in preventing a depressive episode.

Lithium, but not lamotrigine, can prevent a manic, hypomanic or mixed episode.

Haloperidol should be used for agitation in patients with delirium.

Bupropion (Wellbutrin):

·         Unique because it boosts both norepinephrine and dopamine

·         Also acts as a nicotinic antagonist and can help stop smoking

·         Can help with weight loss

·         Does not cause sexual dysfunction like other antidepressants

·         Can increase seizures in those with eating disorder, do not use in them

For some reason, people with a history of eating disorders are more likely to experience Wellbutrin-related seizures. May also trigger a relapse of eating disorders due to weight loss effect.

Bupropion can be used for smoking cessation in those with nicotine addiction.

SSRIs may increase bleeding risk because they prevent serotonin from being taken up into platelets, which can make it harder for them to form

Disulfiram should not be taken for at least 12 hours after drinking alcohol. Reaction can occur up to 2 weeks after discontinuing. May elevate liver function tests. Avoid anything containing alcohol (mouthwash, vinegar, aftershave, cough medication) while using disulfiram and for 2 weeks after.

Carbamazepine can cause Stevens-Johnson syndrome (rash, flu-cllike symptoms, fever) in patients of Asian descent. Need to test for HLA-B allele prior to prescribing it to Asians.

Carbamazepine may be better than lithium when treating rapid-cyclers and mixed episodes. Carbamazepine is good for treating interictal (between seizures/epilepsy) psychosis and mood symptoms secondary to temporal lobe epilepsy. Carbamazepine is effective for pain syndromes like trigeminal neuralgia, postherpetic neuralgia, diabetic neuropathy, phantom limb pain, and multiple sclerosis. Carbamazepine can manage behavioral outbursts and withdrawal of benzodiazepines or alcohol. Over 50% of patients have side effects when using carbamazepine. Common side effects: diplopia, blurry vision, ataxia, GI symptoms, weight gain Less common side effects: skin rash, leukopenia (mild and asymptomatic), thrombocytopenia, hyponatremia, and (rarely) hypo-osmolality. Rare side effects: agranulocytosis, aplastic anemia, hepatic failure, Stevens-Johnson syndrome, and pancreatitis. 5-15% of patients on carbamazepine have elevated LFTs. Will occur within first 6 months of treatment (idiosyncratic). Decreasing carbamazepine dose can resolve leukopenia, thrombocytopenia, or elevated LFTs.

Carbamazepine overdose: altered mental status, ataxia, dizziness, diplopia, nystagmus, opthalmoplegia (eye that is fixed in position), cerebellar and EPS, breathing problems, altered mental status, and convulsions.

Divalproex (Depakote) overdose symptoms: drowsiness, ataxia, tachycardia, nystagmus (uncontrollable rapidly moving eyes)

Lamotrigine overdose symptoms: altered mental state, convulsions, tremor, and impairment of consciousness ranging in severity to deep coma

Atypical/second generation antipsychotics (like aripiprazole) can cause blood sugar issues, so monitor for diabetes

Flumazenil is the antidote for benzodiazepine overdose. Has a shorter half-life than most benzos. Must give in repeated doses to be effective.

Methadone treatment has led to a decrease in unemployment rates, drug overdose deaths, HIV risk behavior and HIV seroincidence, and has succeeded in attracting, retaining, and benefitting large numbers of drug users.

Management of acute opioid withdrawal involves a combination of general supportive measures in conjunction with pharmacotherapy. Treatment consists of short-term detoxification and long-term maintenance. Methadone, clonidine, buprenorphine, and clonidine-naltrexone are used for opioid detoxification.

Methadone, buprenorphine, and naltrexone are used for opioid maintenance therapy.
Ultra-rapid opioid detoxification is less recommended but uses general anesthesia with propofol or conscious sedation with midazolam as well as naltrexone (or naloxone), ondansetron (an entiemetic), octreotide (an antidiarrheal), clonidine, and other benzos.

Desipramine is a TCA that can cause multiple heart problems and sudden death in children.

Desipramine selectively blocks norepinephrine.

Desipramine, amoxapine, and nortriptyline are the least anticholinegic.

TCAs can take 2-4 weeks to begin working.

·         Sedation is big, may even be used as sleeping pills.

·         They prevent reuptake of norepinephrine and serotonin

TCAs are used for treatment of mood disorders and childhood enuresis.

Guanfacine is an alpha-agonist used to treat anxiety in children.

Monitor liver enzymes when giving phenothiazines (like fluphenazine)

Topiramate, phenobarbital, phenytoin and carbamazepine induce CYP450 and increase the metabolism of progestins and estrogens up to 50%, which can cause contraceptive failure

·         Dosages of topiramate greater than 200 mg can affect ethinyl estradiol

Trihexyphenidyl/Artane is an anticholinergic that can decrease symptoms of Parkinsonism and EPS caused by neuroleptics

Benztropine (Cogentin) and trihexyphenidyl (Artane) are anticholinergic medications used to treat extrapyramidal side effects, also in neuroleptic malignant syndrome

Anticholinergic side effects include dry mouth, sedation, blurred vision, fever, urinary retention, agitation, confusion, and seizures.

Propanolol and other beta-blockers can treat antipsychotic-induced akathisia.

Propanolol can increase T4

Bromocriptine (Parolodel) is a direct acting dopamine receptor agonist to help decrease the dopamine blockade in neuroleptic malignant syndrome

Dantrolene (Dantrium) is a muscle relaxant for neuroleptic malignant syndrome

Citalopram (Celexa) has heart effects and can cause abnormal electrical activity in the heart. Do not prescribe above maximum dose of 40 mg.

Isotretinoin is a known teratogen that causes facial and cardiac anomalies.

Diethylstilbestrol (DES/estrogen) causes vaginal adenocarcinoma

Tetracylcline causes enamel hypoplasia and discolored teeth

False positives :

  • Bupropion (Wellbutrin) can give a false positive for meth
  • Amoxicillin or NSAIDs can give a false positive for cocaine
  • Codeine can give a false positive for methadone or PCP
  • Sertraline (Zoloft) can give a false positive for benzos
  • Nyquil can produce a false positive for methadone
  • Valium can produce a false positive for alcohol

Guanfacine (Intuniv) and Strattera (atomoxetine) are FDA non-stimulants for ADHD treatment.

Methylphenidate and guanfacine can only be used in children age 6 and older for ADHD.

Amphetamines can be used in ADHD in children 3 and older.

Adderall can be used to treat ADHD in children.

Fluoxetine and bupropion cannot be used in children under the age of 8 for ADHD.

Fluoxetine is the only SSRI medication approved by FDA for depression in children and teens.

Fluoxetine can be used for OCD in children 7 and older.

Clonidine (Kapvay) is FDA approved non-stimulant for ADHD also in children

Buspirone is a serotonin partial agonist.

Oxazepam is the best benzodiazepine for elderly because it does not require phase I metabolism and is short acting. Phase I metabolism becomes less efficient with age and is accomplished by CYP450.

Stimulant medications are first-line for ADHD.

If a stimulant does not work, switch to another stimulant. If that doesn’t work, try atomoxetine, an inhibitor of the presynaptic norepinephrine transporter, or an alpha agonist.

Lorazepam good for those with hepatic problems and can treat catatonia in schizophrenia.

Lorazepam can be used for medically managed alcohol detox for those with liver problems. It does not produce active compounds and is cleared from the body more quickly than other benzodiazepines.

Lorazepam is long-acting.

Lorazepam first choice for status epilepticus. Then phenytoin. Then phenobarbital. If that fails, try calproate, propofol, midazolam, levetiracetam, or as a last resort general anesthesia.

Levetiracetam is not metabolized by CYP450 enzymes and has the least effect on the CYP450 system.

Sildenafil works by inhibiting phosphodiesterase to reduce cGMP degradation.

Sildenafil interacts with nitroglycerin by increasing nitric oxide levels and enhancing the production of cGMP.

cGMP is a second messenger molecule that modulates various downstream effects, including vasodilation, retinal phototransduction, calcium homeostasis, and neurotransmission.

Administering sildenafil and nitroglycerin together raises the cGMP level and can cause dangerous vasodilation, shock, and syncope.

Schedule I: Tightly regulated. Heroin, LSD, and ecstasy are part of this schedule.

Schedule IV: Drugs with a low risk for abuse or dependence. All benzodiazepines are schedule IV drugs. Many sedatives like meprobamate, chloral hydrate, and phenobarbital are schedule IV. Modafinil and phentermine are schedule IV stimulants. Pentazocine and butorphanol are analgesics that are schedule IV.

Paroxetine and sertraline are SSRIs and can be used for PTSD

TCAs can be used for PTSD but are not as good as SSRIs.

Antipsychotics can be used for PTSD flashbacks.

Olanzapine combined with fluoxetine is FDA approved for bipolar depression and treatment-resistant depression.

Topirmate can cause bleeding if used with phentermine.

Topiramate can cause failure of contraception if used alone.

Phentermine alone is used for short-term weight management.

TCAs interact with MAOIs

Antipsychotics such as Seroquel and Risperdal can cause blurry vision and cataracts. Should have routine eye exam every six months while being treated with antipsychotics.

  • Enzyme inducers: decrease the serum level of other drugs that are substrates of that enzyme, possibly resulting in subtherapeutic levels
      * Carbamazepine, hypericum (St. John’s wort), phenytoin, phenobarbital, and tobacco are all enzyme inducers
      * Carbamazepine stimulates the transcriptional upregulation of genes involved in its own metabolism, which is called autoinduction. This causes autoinduction of CYP3A4 and CYP2D6. Autoinduction is usually complete 3-5 weeks after the intiation of a fixed dose when taken consistently.
  • Enzyme inhibitors: can increase the serum level of other drugs that are substrates of that enzyme, possibly resulting in toxic levels.
      * Bupropion, clomipramine, duloxetine, fluoroquinolones, nefazodone, and SSRIs are enzyme inhibitors

Clozapine is an atypical antipsychotic that can cause lots of weight gain and sedation.

Clozapine has a black box warning for seizure risk.

All antipsychotics lower the seizure threshold and thus could cause seizures, but clozapine the most.

Clozapine may reduce WBC counts. Discontinue clozapine if WBC are 2,000 to 3,000 or granulocytes are 1,000 to 1,500 for agranulocytosis and severely compromised immune system.

Clozapine requires a CBC with differential weekly for the first 6 months.

Clozapine is the only known antipsychotic to reduce suicide risk in schizophrenic patients.

Clozapine may be effective in treating drug-induced psychosis for patients with Parkinson’s disease.

At a WBC of 4,000 it is recommended to continue clozapine but closely monitor CBC with differential twice a week as long as there are no other signs or symptoms.

Tobacco induces clozapine, which means that it increases the metabolism of clozapine through CYP1A2 so that there is less of it available in the bloodstream. So if a patient stops taking tobacco, they may need a lower dose of clozapine.

Amoxapine is a TCA that can cause Parkinson-like symptoms

Risperidone is an atypical antipsychotic that can treat aggression, delusions, and hallucinations in patients with thought disorders.

Risperidone can treat behavior problems in patients with Tourette syndrome.

Risperidone can be used for autism-related irritability in children ages 5-16 years old.

Risperidone has been associated with neuroleptic malignant syndrome.

Prolonged use of risperidone can elevate blood sugar levels and can cause diabetes mellitus. Must monitor fasting glucose levels throughout risperidone therapy.

Risperidone has the greatest risk of elevated prolactin.

Ziprasidone is an atypical antipsychotic medication. Its side effects include hypotension, sedation, dizziness, and prolongation of the QTc interval.

Ziprasidone is the least likely to cause weight gain and has been shown to lower triglyceride levels. For patients at an increased risk for developing metabolic syndrome, ziprasidone is the antipsychotic of choice.

You must monitor for QTc prolongation with ziprasidone.

Taking ziprasidone with food increases absorption twofold.

You should use caution when administering ziprasidone to patients at risk of hypokalemia or hypomagnesemia, after myocardial infarction, or with congestive heart failure.

Benzodiazepines work by binding to GABA, which increases the inhibitory GABA effects.

Flurazepam is a long-acting benzo.

Diazepam and chlordiazepoxide are long-acting benzos.

Oxazepamis is a short-acting benzo.

Midazolam is a short-acting benzo.

Triazolam is a short-acting benzo. Triazolam has the shortest half-life and most rapid absorption.

Depakote may raise ammonia levels.

Anticonvulsants are mood stabilizers

Lamotrigine has an elimination half-life of 25 hours.

Rash is seen in 10% of patients on lamotrigine.

Aripiprazole/Abilify has the lowest sedation of all antipsychotics.

Patients being started on medication for major depressive disorder should be on medication for a minimum of 6 to 12 months. It is important to inform the patient that the therapeutic effect of antidepressants may take at least 4 to 6 weeks to develop.

Orthostatic hypotension is an antiadrenergic side effect.

Weight gain is an antihistaminergic side effect.

Oral contraceptives can decrease calcium levels.

Corticosteroids can induce mania in patients with bipolar disorder.

Beta blockers, benzodiazepines, and retroviral agents cause an exacerbation of depressive symptoms

Trazodone is a serotonin modulator for depression. Trazodone is sedative. Trazodone may cause rare but serious priapism (painful persisting erection). Priapism can be treated with the decongestant phenylephrine.

Selegiline is an MAOI used to treat Parkinson’s and is contraindicated with the opiate meperidine due to risk of hypertensive crisis and death.

SSRIs can cause hyponatremia.

Anorgasmia is the most commonly reported sexual dysfunction side effect in women who are taking SSRIs

Symptoms of hyponatremia include nausea, headache, feeling weak, and decreased appetite.

The following common medications can induce depression:

  • Beta blockers such as propranolol
  • Steroids
  • Interferon
  • Isotretinoin
  • Some retroviral drugs
  • Neoplastic drugs
  • Benzodiazepines
  • Progesterone

The following medications can induce mania:

  • Steroids
  • Disulfiram
  • Isoniazid
  • Antidepressants

Must eat 360 calories with lurasidone for proper absorption.

Psychotropic medications are lipophilic and highly protein-bound. Older adults are more sensitive to psychotropic medications due to their

  • Decreased intracellular water
  • Low muscle mass
  • Decreased protein binding
  • Increased body fat concentration
  • Decreased rate of metabolism