November 16, 2022


💊 Lithium is a common ‘mood stabilizer’ used to treat the manic episodes of bipolar disorder, a mood disorder that is characterized by episodes of mania, hypomania, and depression. ⁠⠀
🤔 The exact cause of bipolar disorder is unknown but is highly linked to family history, genetics, and abnormalities in neurotransmitters. This makes it tricky to pinpoint exactly how lithium works to treat bipolar but there are many proposed mechanisms of action. ⁠⠀
🧠 Whenever you see the medication lithium, always think SALT as lithium (Li+) is located close to sodium (Na+) on the periodic table and they share similar structures. Because of this, lithium levels are often affected by salt and water balance as well as renal function (excreted mainly through kidneys). ⁠⠀
💦 Dehydration can cause lithium levels to increase while increasing sodium intake can cause lithium levels to decrease. Medications that affect water and salt balance (ex: diuretics, NSAIDs, ACEI) can also alter lithium concentrations. ⁠⠀
🗓️ The starting dose of lithium is 300 mg two or three times a day (The brand name is Lithobid to help you remember that it can be given BID or twice daily)⁠⠀
🤰🏻Lithium is considered teratogenic due to the potential for fetal cardiac defects. The risks and benefits should be discussed with a healthcare provider before starting it in women of childbearing age.⁠⠀
⭐ Lithium is a popular drug that often shows up on tests due to its narrow therapeutic index and many side effects. ⁠⠀

ACE-inhibitors ⁠

 Let’s talk about ACE-inhibitors ⁠⠀
💊 Angiotensin-converting enzyme (ACE) inhibitors are a class of drugs mainly used in the treatment of hypertension and heart failure with reduced ejection fraction (HFrEF). They are one of the top 200 drugs prescribed and because of that, they are an important class to know. ⁠⠀
⭐ Drugs in this class end in the suffix ‘-pril’ such as: ⁠⠀
❗Do not use this medication in patients who: ⁠⠀
-Have a hypersensitivity to ACE inhibitors or any of their components⁠⠀
-Pregnant or breastfeeding: box warning for patients who are or may become pregnant as it can cause fetal toxicity⁠⠀
-History of angioedema, bilateral renal stenosis, and concurrent use with aliskiren in patients with diabetes⁠⠀

Chronic Kidney Disease

 Renal adjustments in CKD and AKI 

😏 Acute kidney injury is not very cute ⁠

💧 Most drugs, particularly water-soluble drugs and their metabolites, are eliminated largely by the kidneys in urine. ⁠

⭐️ It is important to know which drugs require dose adjustments to prevent accumulation and toxicity in patients with chronic kidney disease (CKD) as well as those with acute kidney injury. ⁠

🤔 Things to keep in mind when renally adjusting medications: ⁠

👉🏻 Use estimated GFR or CrCl to determine drug dosing⁠
👉🏻 If the patient is on hemodialysis, the type of HD will also determine drug dosing⁠
👉🏻 CrCl should be monitored periodically in patients with AKI to determine if doses need to be adjusted when CrCl improves⁠
👉🏻 Some medications require individualized therapy (ex: serum drug level monitoring, vital signs, adverse effects) when dose adjusting⁠


🌧️ Major depressive disorder (MDD) is a mood disorder characterized by persistent feelings of sadness and loss of interest that interferes with normal daily functioning.⁠

⭐️ The exact chemical basis for depression is poorly understood but is thought to be linked to decreased levels of the neurotransmitters, serotonin, dopamine, and norepinephrine. This cause is also known as the monoamine hypothesis.⁠

👉🏻 Because of this, the drugs developed to treat MDD selectively target the reuptake of serotonin and norepinephrine, increasing levels of these neurotransmitters in the synapse and enhancing NT signaling.⁠

⭐️ SSRIs are generally first-line due to their improved tolerability compared to the others (TCAs and MOAIs) and relative safety in cases of overdose.⁠

⭐️ Studies have shown equivalent efficacy among antidepressants, therefore the initial choice is made empirically based on patient factors and the nuances of each drug.⁠

5-HT3 Inhibitors

💊 5-HT3 Inhibitors (ex: ondansetron) ⁠

🤢🤮 Nausea and vomiting are two of the most common presenting complaints ⁠

5-HT3 inhibitors (such as ondansetron) are one of the top 200 drugs prescribed and are used for the prevention of:⁠
🌟 chemotherapy-induced nausea and vomiting⁠
🌟 radiation-induced nausea and vomiting⁠
🌟 postoperative nausea and vomiting⁠
🌟 off-label for nausea and vomiting associated with pregnancy