Hypoventilation (also known as respiratory depression) occurs when ventilation is inadequate (hypo meaning "below") to perform needed respiratory gas exchange. By definition it causes an increased concentration of carbon dioxide (hypercapnia) and respiratory acidosis. Hypoventilation is not synonymous with respiratory arrest, in which breathing ceases entirely and death occurs within minutes due to hypoxia and leads rapidly into complete anoxia, although both are medical emergencies. Hypoventilation can be considered a precursor to hypoxia and its lethality is attributed to hypoxia with carbon dioxide toxicity. Causes
Hypoventilation may be caused by:

A medical condition such as stroke affecting the brainstem
Voluntary breath-holding or underbreathing, for example, hypoventilation training or the Buteyko method. Medication or drugs, typically when taken in accidental or intentional overdose. Opioids and benzodiazepines in particular are known to cause respiratory depression. Examples of opioids include pharmaceuticals such as oxycodone and hydromorphone and examples of benzodiazepines include lorazepam and alprazolam. Hypocapnia, which stimulates hypoventilation
Obesity; see Obesity hypoventilation syndrome
Chronic mountain sickness, a mechanism to conserve energy. Medications
As a side effect of medicines or recreational drugs, hypoventilation may become potentially life-threatening. Many different central nervous system (CNS) depressant drugs such as ethanol, benzodiazepines, barbiturates, GHB, sedatives, and opioids produce respiratory depression when taken in large or excessive doses, or mixed with other depressants. Strong opiates (namely fentanyl, heroin, and morphine), barbiturates, and certain benzodiazepines (such as alprazolam) are known for depressing respiration. In an overdose, an individual may cease breathing entirely (go into respiratory arrest) which is rapidly fatal without treatment.
Potassium citrate (also known as tripotassium citrate) is a potassium salt of citric acid with the molecular formula K3C6H5O7. It is a white, hygroscopic crystalline powder. It is odorless with a saline taste. It contains 38.28% potassium by mass. In the monohydrate form, it is highly hygroscopic and deliquescent. As a food additive, potassium citrate is used to regulate acidity, and is known as E number E332. Medicinally, it may be used to control kidney stones derived from uric acid or cystine. Synthesis
Potassium citrate can be synthesized by the neutralization of citric acid which is achieved by the addition of potassium bicarbonate, potassium carbonate or potassium hydroxide to it. The solution can then be filtered and the solvent can be evaporated till granulation. Uses
Potassium citrate is rapidly absorbed when given by mouth, and is excreted in the urine. Since it is an alkaline salt, it is effective in reducing the pain and frequency of urination when these are caused by highly acidic urine. It is used for this purpose in dogs and cats, but is chiefly employed as a non-irritating diuretic. Potassium citrate is an effective way to treat/manage gout and arrhythmia, if the patient is hypokalemic. It is widely used to treat urinary calculi (kidney stones), and is often used by patients with cystinuria.