Pharm Quiz 4 Hard

Drugs for Parkinson's Disease

• Levodopa is considered the most effective drug for managing Parkinson's Disease (PD) symptoms
• Full therapeutic effects of Levodopa may take several months to manifest
• Levodopa functions by increasing dopamine synthesis in the striatum
• Levodopa is rapidly absorbed in the small intestine, with only a small fraction reaching the brain
• Levodopa can cause adverse effects, including nausea/vomiting, dyskinesias, postural hypotension, dysrhythmias, and psychosis
• Levodopa interacts with drugs like Haldol and MAOIs
• High-protein meals can reduce therapeutic response.

Levodopa/Carbidopa Combination

• Levodopa/Carbidopa is a highly effective therapy
• Carbidopa enhances the effects of levodopa when combined
• Carbidopa does not have adverse effects when taken alone

Dopamine Agonists

• Dopamine agonists can be used as first-line drugs for Parkinson's Disease
• Dopamine agonists are associated with severe side effects like hallucinations, daytime sleepiness, and postural hypotension
• Pramipexole and Ropinirole are examples of nonergot derivatives

MAO-B Inhibitors

• Selegiline selectively and irreversibly inhibits MAO-B
• Selegiline can cause insomnia and orthostatic hypotension as adverse effects
• Selegiline interacts with drugs like Levodopa, Meperidine, and SSRIs
• Amantadine inhibits dopamine uptake
• Amantadine can cause confusion, lightheadedness, anxiety, blurred vision, urinary retention, and constipation as adverse effects

Alzheimer's Disease

• Alzheimer's Disease is characterized by neuronal degeneration in the hippocampus and a decline in cerebral volume
• Early symptoms include short-term memory loss, language difficulties, and speech impairment
• Symptoms of Alzheimer's Disease progress from mild to moderate to severe
• Treatment may slow memory and cognitive decline and prolong independent function

Cholinesterase Inhibitors

• Cholinesterase inhibitors work by preventing the breakdown of acetylcholine
• Cholinesterase inhibitors are approved for mild to moderate symptoms of Alzheimer's Disease
• Cholinesterase inhibitors offer modest and short-lasting improvements
• Cholinesterase inhibitors can cause nausea/vomiting/diarrhea, dizziness, headache, and bradycardia as adverse effects
• Cholinesterase inhibitors interact with first-generation antihistamines, TCAs, and antipsychotics
• Preparations include Donepezil, Rivastigmine, and Galantamine

Memantine

• Memantine is indicated for moderate to severe Alzheimer's Disease symptoms
• Memantine modulates the effects of glutamate
• Memantine can cause dizziness, headache, and confusion as adverse effects

Drugs for Epilepsy and Seizure Types

• Seizures can be categorized into partial (simple, complex, secondarily generalized) and generalized types
• Generalized seizures include tonic-clonic, absence, atonic, myoclonic, status epilepticus, and febrile seizures

Anti-Seizure Medication Mechanisms

• Anti-seizure medications work by suppressing sodium influx
• These medications also reduce calcium influx
• These drugs promote potassium efflux
• Anti-seizure medications antagonize glutamate
• The medications potentiate GABA

Epilepsy Diagnosis and Drug Selection

• It's imperative to accurately diagnose the type of seizure to match the appropriate medication
• Finding an effective regimen may require trying several drug combinations
• Managing epilepsy requires monitoring plasma drug levels

Traditional Anti-Epileptic Drugs

• Phenytoin is the most widely used traditional antiepileptic drug
• Phenytoin works through selective inhibition of sodium channels
• Absorption of Phenytoin varies among oral forms
• Phenytoin's metabolism has limited capacity by the liver
• Nystagmus, gingival hyperplasia, measles-like rash, cardiac dysrhythmias, and hypotension (IV form) are adverse effects of Phenytoin
• Phenytoin can cause drug interactions with oral contraceptives, Warfarin, Glucocorticoids, Diazepam, and Alcohol

Carbamazepine

• Carbamazepine suppresses high frequency neuronal discharge in and around seizure foci
• Absorption of Carbamazepine delayed and variable
• Carbamazepine is metabolized by the liver
• Adverse effects of Carbamazepine can include blurred vision, diplopia, leukopenia, anemia, and aplastic anemia
• Carbamazepine interacts with Phenytoin, Phenobarbital, and Grapefruit juice

Valproic Acid

• Valproic acid is effective for treating all seizure types
• Valproic acid suppresses high frequency neuronal discharge
• The drug is readily absorbed from the GI tract
• Valproic acid can cause hepatotoxicity, pancreatitis, and nausea/vomiting as adverse effects
• Valproic acid interacts with Phenobarbital, Phenytoin, and Topiramate

Phenobarbital

• Phenobarbital potentiates the effects of GABA
• The drug shows complete absorption and is metabolized by the liver
• Adverse effects include drowsiness and physical dependence
• Phenobarbital interacts with CNS depressants and Valproic acid

Newer Anti-Epileptics

• Oxcarbazepine blocks voltage-sensitive sodium channels
• Oxcarbazepine may cause dizziness, drowsiness, double vision, headache, and nausea/vomiting advese events
• Oxcarbazepine interacts with oral contraceptives, alcohol, and diuretics
• Lamotrigine blocks sodium channels
• Lamotrigine has adverse effects like dizziness, diplopia, and blurred vision
• Oral contraceptives, alcohol, and diuretics interact with Lamotrigine
• Gabapentin's mechanism is unknown
• The drug is rapidly absorbed after oral administration
• Somnolence and dizziness are adverse reactions
• Levetiracetam has unknown action
• The drug has rapid, complete absorption after oral administration
• Drowsiness and weakness are adverse effects
• Topiramate absorption is rapid after oral administration
• Somnolence, dizziness, ataxia, and nervousness are adverse reactions of Topiramate
• Phenytoin and carbamazepine interact with Topiramate

Diabetes and Sulfonylureas

• Sulfonylureas include first-generation drugs like acetohexamide, chlorpropamide, tolazamide, and tolbutamide
• Second generation drugs: glyburide, glipizide, glimepiride etc.
• Sulfonylureas, used for diabetes, act as insulin secretagogues, stimulating the pancreas to release insulin, thus lowering blood sugar by stimulating insulin release
• There's no therapeutic difference between first- and second-generation drugs, though second-generation drugs have fewer adverse effects, except hypoglycemia, and fewer drug interactions
• Sulfonylureas are best for normal weight adults lacking lipid abnormalities
• Sulfonylureas inhibit the potassium channel in pancreatic beta cells, resulting in depolarization and enhanced insulin secretion of calcium channels
• Adverse effects include hypoglycemia, nausea, epigastric fullness, heartburn, and weight gain
• Sulfonylureas can also cause skin reactions like pruritus, erythema, urticaria in 1.5%
• Liver function should be monitored
• Clinically, sulfonylureas are first-line oral agents for type 2 diabetes, effective, inexpensive (if generic), but metformin is often preferred for overweight patients

Meglitinides

• Meglitinides consist of the non-sulfonylurea part of glyburide, sharing a similar mechanism of action to treat type 2 diabetes
• Meglitinides, like nateglinide and repaglinide, have a faster onset and shorter duration of action compared to sulfonylureas and lowers blood glucose
• Meglitinides are great for patients that do not maintain a regular meal schedule
• These acting secretagogues lower blood glucose levels by stimulating the release of insulin from the pancreas by interacting with binding sites on the potassium channel in the pancreatic beta cell membrane and its beta cells
• Being able to use this drug with metformin is also useful
• Meglitinides are administered 15-30 minutes prior to eating a meal for decreased hyperglycemia
• Because it needs to be given with each meal, it can be inconvenient

Biguanides and Metformin

• Metformin is the primary and only drug in the biguanide class that treats those with diabetes
• Metformin reverses diabetes defects by reducing hepatic glucose production (hepatic gluconeogenesis), increases peripheral glucose utilization, and reduces intestinal glucose production
• Metformin does NOT increase insulin secretion and is not associated with hypoglycemia
• Side effects of metformin include GI issues like diarrhea, nausea, vomiting etc (30% of patients)
• Metformin may interfere with B12 absorption, and increase lactate levels
• Has a BLACK BOX warning for possible lactic acidosis if there is hepatic failure, cardiac failure and renal failure
• Metformin is not suitable for those at risk of developing acute renal failure, shock, acute CHF, MI, septicemia, or liver disease
• LFTs and creatinine levels should be checked before initiating metformin

Thiazolidinediones (TZDs)

• TZDs used to treat diabetes include pioglitazone (Actos) and rosiglitazone (Avandia), sometimes combined with metformin
• They decrease insulin resistance at peripheral sites and in the liver
• TZDs cause activation of insulin-responsive genes in the nucleus that regulates lipid and carbohydrate metabolism
• TZDs are generally well-tolerated by patients but may cause hypoglycemia
• Peripheral edema may occur within 6 months of therapy
• Rare causes of severe idiosyncratic hepatocellular injury were reported with the use of troglitazone (Rezulin)
• Monitor LFT's if a patient is on rosiglitazone and pioglitazone
• TZDs are often used for those with renal dysfunction however can be expensive.

Alpha-Glucosidase Inhibitors

• Used to treat diabetes
• Drugs include: Acarbose (Precose); Prandase miglitol (Glyset)
• Alpha-glucosidase inhibitors delay and decrease the absorption of complex carbohydrates from the GI tract, which lowers postpranial glucose levels
• The drugs cause GI side effects
• Acarbose and miglitol can be used as first-line or adjunctive drugs, but patients need to treat hypoglycemia with glucose tablets or glucagon injection
• These drugs are for those with FBS levels

Dipeptidyl peptidase-4 (DDP-4) Inhibitors

• Used to treat diabetes
• Drugs include: Januvia, Onglyza, Tradjenta
• DPP-4 inhibitors, also known as gliptins work by enhancing the incretin system in the body. This lowers blood glucose levels
• When the body senses hyperglycemia in response to a glucose load, incretins stimulate beta cells in the pancreas to release insulin and decrease glucagons secretion from alpha cells, which signals the liver to cease glucose production. The DDP-4 enzyme breaks down endogenous incretins, resulting in more incretin in the body
• Side effects of DDP-4 inhibitors are nasopharyngitis, URI, headaches, hypersensitivity reaction.
• Used to aid diet and exercise to better control diabetes
• Can be used to control glucose in DM

Thyroid Disorders - Hypothyroidism

• Hypothyroidism is more common in women, affecting 1.5-2% versus 0.2% in men and incidence increases with age
• Primary Hypothyroidism is causes by Thyroid hormone issue
• Can be caused by other treatments and diseases
• Primary: Inadequate thyroid hormone production
• Secondary: Hypothalamic Pituitary
• Fatigue, constipation, weight gain are signs of Hypothyroidism

Thyroid Replacement Therapy

• Used to treat hyperthyroidism
• Synthroid, generic is the best product since T3 is produces as needed from T4
• Dosage changes should occur every 4 to 6 weeks to check hormone levels

Hyperthyroidism

• Toxic Modulator is more common in women over 55
• Can be caused by Graves disease

Drug Therapy for Hyperthyroidism

• Methimazole (preferred) or PTU (pregnant)
• PTU or Methimazol should be given an hour before iodide to prevent oxidation of iodine

Drugs and Treatment of PUD and Gerd

• Toxins and enzymes that promote inflammation and ulceration
• Drugs that cause inflammation should be avoided
• Treatment includes a PPI plus antibiotics

Gerd

• Gerd medication that lowers pain and lowers amount of acid given is key
• PPI is the best to give
• Histamine type 2 is second
• If used as an antacid, this does not help with all of the above, but neutralizes what is there

Overactive Bladder

• Symptoms: urgency, frequency, nocturia, urge incontinence Anticholinergic therapy include Oxybutynin, Darifenacin, Solifenacin, Tolterodine, Fesoterodine, trospium Side effects: Dry mouth, blurry vision, constipation, drowsiness, sedation, hallucinations, memory problems, confusion, delirium, decreased sweating and saliva

Oral Contraceptives

• Transnormal patches or vaginal rings are great combination
• Lowers risk for PID

Erectile Disfunction

• Take viagra
• Be careful of drugs used

Finasteride for prostrate treatment

• FDA warning: Perform appropriate eval to rule out other urological conditions, such as prostate CA, that may mimic BPH

Laxatives

• Osmotics include milk of magnesia, sodium phosphate, and miralax

Explore the use of Levodopa and dopamine agonists in managing Parkinson's Disease symptoms. Levodopa increases dopamine synthesis but has adverse effects and drug interactions. Carbidopa enhances levodopa's effects reducing the required dosage.