Kidney Disease Risk From Lithium In Bipolar Disorder Treatment
In the treatment of bipolar disorder, Lithium-based therapies had been giving encouraging results when tried on a long term basis with an average recovery rate of 30 to 40 percent.
Benefits apart, the main concern over patients with lithium exposure is the impairment it causes to the kidneys. Some medical studies have implicated Lithium as a causative factor for chronic tubulointerstitial nephritis and other renal disorders.
Bipolar disorder manifests as extreme mood swings and severe depression. That is why it is also called manic depression.
However, studies have eulogized the medical benefits of lithium treatment and its contribution in reducing risks of stroke, cancer, dementia, heart disease, and neurologic illnesses.
Here we will examine lithium’s role as a mood stabilizer playing a positive role in curing bipolar disorder patients and its potential of renal damage when used long-term plus the ways to curb its adverse effects.
The positive attribute of lithium is that it curbs both the frequency and severity of bipolar disorder episodes in a person. Bipolar depression is also controlled by Lithium dosages.
Studies show lithium significantly reduces suicide risk as well and prevent recurring manic and depressive episodes. As a result, Lithium is prescribed for longer periods as maintenance therapy.
According to research, lithium works on the central nervous system, which is comprised of the spinal cord and brain. It is believed to strengthen the nerve cell connections in the brain areas that control mood, behavior, and thinking.
Lithium and kidney damage
Studies that looked at renal damage from lithium exposure have noted that its long-standing use can cause renal heath to suffer.
Adding to the problem is that bipolar disorder, itself a very difficult condition to live with, often comes accompanied by a slew of additional co-morbid conditions including hypertension, cardiovascular diseases and diabetes, all of which also affect the kidneys.
One reason why research has not established any strong link between lithium and renal impairment could be the lack of controlled data. However, many medical studies have flagged the risk emanating from anticonvulsants to the kidneys moreso than lithium.
The former includes drugs used in treating seizure disorders. The confusion has stemmed from the use of uncontrolled data, according to experts.
Renal problems from lithium exposure usually take at least 30 years to express. So, a controlled trial lasting that long is not practical and the results are unlikely to establish any evidence of serious damage potential. However, despite limitations, the available data offers the following inferences.
- Lithium impairs the kidneys by hampering the glomerular filtration rate
- But lithium-based impairments seldom lead to end-stage renal disease
- Anticonvulsants create side effects that can impact kidneys.
The main concern about lithium-related renal dysfunction has been the toxicity induced by lithium that kills renal cells. Studies show that lithium will not hurt when the dosage stays below the toxic limit of 0.8 mmol/L (millimoles per liter) but kidney damage begins whenever those levels being to exceed the safe limits.
The higher dose of 1.2 mmol/L is required only when acute mania exists.
Keep dosage low
It is apparent that a lower lithium dosage can safeguard renal health. Ideally, the dosage level must stay lower when the subject’s age is higher.
In contrast to the level of 0.4-0.6 mmol/L for patients above 60, younger adults can have a benign dosage of 0.6-0.8 mmol/L.
The caution regarding older people is attributed to the risks from the more porous nature of the brain in the aged and the subsequent chances of more lithium ingress into the central nervous system even if the serum level is low.
Single dose for a day
Prudent use of lithium can be a positive way of saving the kidneys while also treating one’s Bi-Polar. Dosing lithium at a single dose in the evening is practiced widely. Given Lithium’s half-life of 18 to 24 hours, capping the intake of milligrams in a single dose makes no sense. The real risks stem from the serum level, while milligram count does not matter as much.
For curing active mania, high serum levels are a must, hence two doses a day may be warranted to avoid toxic peaks.
The toxicity level differs from patient to patient. For older patients, 0.8 level will be too toxic while younger adults can withstand more toxicity and it will stay muted even at 1.2 mmol/L.
Drinking and urinating too much
The adverse effects of lithium include Polyuria and Polydipsia. The former is frequent urination and second is high water intake caused by huge thirst.
The most severe expression will be as Nephrogenic diabetes insipidus (NDI) lessening the kidneys’ ability to concentrate the urine caused by the changes in the renal tubules.
Curing NDI involves skipping lithium plus administering Amiloride, a diuretic that checks the progression of renal problems by halting the fibrotic changes of kidneys.
But a doctor’s guidance is crucial because of the risk of hyperkalemia in patients with diabetes. The diagnosis NDI condition is confirmed by tracking urine osmolality, serum creatinine, urine sodium, serum sodium, and a volume check of 24-hour urine ouput.
Use of N-Acetylcysteine (NAC) offers protection and relief to most renal issues including lithium-borne toxicity. This antioxidant is available as capsules. Sometimes, it does elicit complaints of constipation, but it is not costly. NAC is also good for addressing bipolar depression.
NAC application in bipolar disorder is usually therapeutically dosed in quantities of 20 mg/day, double the volume used for renal protection at 10 mg/kg. Prominent NAC brands on the market include Life Extension, Doctor’s Best, Nutricost, and NOW.
Renal Health check-up
Those on lithium dosage have to monitor their renal health at least every 6 months. Creatinine as a metric may look adequate but a reliable benchmark will be the estimated glomerular filtration rate (eGFR) derived from the creatinine level as a right pointer.
Before concluding, let us make note of the fact that any abrupt cessation of lithium will be risky and a tough call. Since there is no prescribed level of renal function as to where exactly the medication must stop, it is better to opt for a calibrated withdrawal.
Stopping lithium all of a sudden can have perilous effects in patients, including renal failure and depression with some even resorting to suicide.
The ideal lithium weaning off will be a gradual reduction spread over a month or many months to cut the risks of relapse and suicide. For more of the latest information on all things kidney-related be sure to subscribe to our newsletter!