Since calcium blocks sodium channels and inhibits depolarization of nerve and muscle fibers, increased calcium raises the threshold for depolarization. This results in diminished deep tendon reflexes (hyporeflexia), and skeletal muscle weakness.Other symptoms include cardiac arrhythmias (especially in those taking digoxin), fatigue, nausea, vomiting (emesis), loss of appetite, abdominal pain, & paralytic ileus. If kidney impairment occurs as a result, manifestations can include increased urination, urination at night, and increased thirst. Psychiatric manifestation can include emotional instability, confusion, delirium, psychosis, and stupor. Calcium deposits known as limbus sign may be visible in the eyes.Symptoms are more common at high calcium blood values (12.0 mg/dL or 3 mmol/L). Severe hypercalcaemia (above 15–16 mg/dL or 3.75–4 mmol/L) is considered a medical emergency: at these levels, coma and cardiac arrest can result. The high levels of calcium ions decrease the neuron membrane permeability to sodium ions, thus decreasing excitability, which leads to hypotonicity of smooth and striated muscle. This explains the fatigue, muscle weakness, low tone and sluggish reflexes in muscle groups. The sluggish nerves also explain drowsiness, confusion, hallucinations, stupor or coma. In the gut this causes constipation. Hypocalcaemia causes the opposite by the same mechanism. Hypercalcaemic crisis
A hypercalcaemic crisis is an emergency situation with a severe hypercalcaemia, generally above approximately 14 mg/dL (or 3.5 mmol/L).The main symptoms of a hypercalcaemic crisis are oliguria or anuria, as well as somnolence or coma.
Brinzolamide/brimonidine, sold under the brand name Simbrinza, is a fixed-dose combination medication used to reduce intra-ocular pressure (pressure inside the eye) in adults with ocular hypertension (high intra-ocular pressure) or in those with an eye condition known as open-angle glaucoma. It contains brinzolamide and brimonidine tartrate. It is used as an eye drop.The most common side effects include ocular hyperaemia (red eye), allergic reactions in the eye, and dysgeusia (taste disturbances).Open-angle glaucoma (a condition where the aqueous humour, the watery fluid inside the eyeball, cannot drain away properly) and other causes of high pressure in the eye increase the risk of damage to the retina and the optic nerve (the nerve that sends signals from the eye to the brain). This can result in serious vision loss and even blindness.The active substances, brinzolamide and brimonidine tartrate, help to reduce intra-ocular pressure by reducing the production of aqueous humour. Brinzolamide works by blocking an enzyme called carbonic anhydrase, which produces bicarbonate needed for the production of the aqueous humour, while brimonidine tartrate blocks another enzyme known as adenylate cyclase, which is also involved in the production of the aqueous humour. Brimonidine also increases the drainage of aqueous humour from the front of the eye.Brinzolamide/brimonidine was approved for medical use in the United States in April 2013, and in the European Union in July 2014. Medical uses
Brinzolamide/brimonidine is indicated to decrease of elevated intraocular pressure (IOP) in adults with open-angle glaucoma or ocular hypertension for whom monotherapy provides insufficient IOP reduction.