1. Digoxin Toxicity
– Most common symptoms are GI: nausea, anorexia, vomiting
– EKG: bidirectional ventricular tachycardia and accelerated junctional rhythm (AV node outpaces SA node due to stimulation and suppression respectively). You also may see scooping T-wave depressions (pretty characteristic of digoxin toxicity)
– Visual symptoms - "yellow halos" around objects
– May be 2/2 verapamil which decreases renal clearance of dig
– Anything that affects renal function/GFR will affect dig levels
– Target levels 0.8-2.2
– Treat with digitoxin Fab (Digibind is >$10,000 per vial). Mag and lidocaine may help. Check and replenish lytes.
2. Vaccinations in HIV
– Generally should not be given live vaccines, except MMR, varicella, zoster and yellow fever if the CD4 count is > 200 & the patient has never had an AIDS defining illness
– Should get TDaP q10, pneumococcus, hep A (MSM only), hep b, HPV
– Meningococcus: same indications as not HIV- college student, military, no spleen, travel to endemic areas
– HiB if not given in infancy
3. Endocrine: 
- Metabolic derangements in hypothyroidism: hyperlipidemia, hyponatremia (from increased water retention), increasing creatinine kinase, transaminitis
- Thyroid disease can affect deep tendon reflexes and muscle tone .
- Low T with low FSH and LH suggest central cause. Should check prolactin levels = if they are high then MRI
- Cushing's can cause shift neutrophilia
- Management of SIADH - fluid restriction and salt tablets -/+ loop diuretics. Hypertonic saline in resistant cases. Demeclocycline is an anti-ADH but It can be nephrotoxic and is rarely used
- Hyperparathyroidism can cause elevated calcium levels in the blood which leads to chondrocalcinosis and pseudogout
- Familial hypocalciuric hypercalcemia has mutated calcium sensing receptors in both kidney tubules and parathyroid gland leading to inappropriately high-normal PTH.
- Calcium to creatinine ratio greater than .02 suggests calcium losing process such as primary hyperparathyroidism; Ca-to-Cr ratio less than 0.01 suggests calcium retaining process such as FHH
- Low Ca AND low phos: think vitamin D deficiency (chronic pancreatitis, decreased absorption of fat soluble vitamins) or acute pancreatitis
- Low C and high phos: primary hypoparathyroidism or pseudohypoparthyroidism (body can't respond to PTH)
- Immobility can cause hypercalcemia: possibly due to increased osteoclastic bone resorption. Usually occurs about 1 month in, but people with renal insufficiency can see it in days. Treat with bisphosphonates.
4. Ectopic ACTH production
– Can occur in small cell and carcinoid
– If ACTH production is slow you will get a cushingoid symptomatology
– If ACTH production is high then You get a hyperaldosteronism picture along with hyperpigmentation. Cortisol has high affinity for mineralocorticoid receptors, however it is normally rapidly converted to inactive cortisone by 11 beta HSD in kidney tubule cells, However the acute and high ACTH production saturates the enzyme.
5. Vitamins: 
- Serotonin syndrome can lead to niacin deficiency; the increased synthesis of serotonin shunts tryptophan away from niacin synthesis. Diarrhea dermatitis dementia and death.
- Vitamin A overdose can cause pseudotumor cerebri. Headaches and blurry vision. Dry skin. Abdominal pain
- B12 deficiency - think pernicious anemia - think gastric cancer
- Give B6 and folate supplements to reduce levels of homocystine in homocystinemia. Homocystine is highly reactive and predisposes to venous clots and atherosclerosis. Homocysteine can be broken down into methionine (requires B12 and folate) or into cysteine (requires B6).
Vitamin K: onset of action 8 to 12 hours when given iatrogenically. Most people have a 30 day supply In the liver but those with underlying liver disease can become deficient in 7 to 10 days
6. Going back to the Pharm: 
- Aspirin hypersensitivity reaction: Shunting of arachidonate acid to leukotrienes by cox inhibitors in susceptible individuals leads to nasal polyps and bronchoconstriction. Treat with leukotriene inhibitors
- Aspirin can cause idiopathic thrombocytopenia
- Primodone is an anticonvulsant that breaks down into phenobarbital. This can precipitate acute intermittent Porphyria. It is used to treat essential tremor.
- Sildenafil should not be combined with nitrates, or any other vasodilators as it can worsen hypotension. If you're administering with alpha blockers like doxazosin, wait 4 hrs in between to prevent hypotension.
- Trihexiphenydil - Anticholinergic like benztropine. Used to treat Parkinson's and dystonia from anti-dopaminergics
- Drugs that can cause pseudotumor cerebri: vitamin a derivatives (all trans retinoic acid, accutane), tetracyclines, growth hormone
- Side effects of epo:  Worsening hypertension, headaches, flu like symptoms, rarely red cell aplasia
- Fluphenazine: high potency typical antipsychotic. Injectable, long lasting. Can inhibit shivering response and lead to significant hypothermia in cold environments.
7. Management of anemia
– Defuroxime to manage iron overload in patients with frequent transfusions (B thal major or sickle cell)
– Folate supplementation in patients with high red cell turnover ie hemolysis (PNH, HS, sickle cell) or B thal
– No treatment for b thal minor
– Prednisone for AIHA
– Indications for epo: CKD anemia, anemia of chronic disease, anemia after bone marrow transplant or chemo
8. More heme: 
- Lupus anticoagulant causes falsely elevated PTT by binding to phospholipids in the test. Mechanism of thrombosis unknown: possibly concentration of antibodies on cell surfaces causing activation of coagulation cascade
- Polycythemia vera causes gout in up to 40% of people. Characteristic pruritus after a hot bath due to increased histamine released from increased basophils. This increased histamine secretion can also lead to gastric ulcer. Splenomegaly.
- Isolated thrombocytopenia: test for hep C and HIV (can cause isolated cytopenias). Other causes: EBV, myelodysplastic (age>60), alcohol, B12 or folate deficiency.
9. Neuro 
- Diplopia after prolonged eye use, dysarthria after prolonged speaking, or jaw fatigue after prolonged chewing = Think myasthenia gravis. CPK will be normal which distinguishes it from primary muscle pathology. Reflexes will be normal which distinguishes it from ALS.  Approximately 15% of those with MG have a thymoma. MG tends to affect bulbar muscles first.
- Alcoholic cerebellar degeneration causes typical cerebellar signs such as dysmetria and dysdiadochokinesia as well as ataxia and truncal ataxia. You can also see muscle hypotonia leading to pendulum swing (striking of patellar tendon leads to slow pendulum like swinging of the leg - more than four swings is considered pathologic)
- Clasp knife rigidity and clonus are pyramidal signs
- Hemineglect: parietal lesion.
- Achilles tendon reflexes often fade With age
- Distinguishing dementia from typical aging. Dementia is:impairment of normal functioning, loss of insight about memory loss and declining functioning (anosognosia), not only expressive but some receptive aphasia, getting lost in familiar environments, losing the ability to remember recent important memories
- After sub-arachnoid or intraparenchymal bleed, you can see cerebral salt-wasting 2/2 SIADH and secretion of BNP (which wastes salt)
10. ID in HIV 
- Causes of dysphagia in HIV patients: Candida most common overall. Causes mild to moderate esophagitis and is usually associated with thrush. Severe pain + no thrush think CMV or HSV
- Candida: empirically treat with 3-5 days fluconazole. If it's resistant you can go to voriconazole, caspofungin or amphotericin
- If there is no thrush or does not respond to treatment you should scope to look for CMV (linear ulcers) or HSV
- Treat apthous ulcers with topical steroids, and if that fails, systemic steroids
- Treat CMV with ganciclovir: CMV does not include the viral thymidine kinase needed for acyclovir to be effective
- Pentamidine is the treatment for PCP pneumonia in AIDS patients who cannot tolerate bactrim