Ezhuthachan College of Pharmaceutical Sciences.
Abiraterone acetate, a selective inhibitor of androgen biosynthesis, is widely used in the treatment of metastatic prostate cancer. Although it is generally well tolerated, rare but serious adverse effects such as interstitial lung disease (ILD) have been documented. We report a case of a 55-year-old male patient with a background history of systemic hypertension, benign prostatic hyperplasia (BPH), chronic kidney disease (CKD), and multiple myeloma on chemotherapy, who developed severe respiratory distress following abiraterone therapy. The patient was admitted with complaints of acute urinary retention, fever with chills, and progressive shortness of breath. He had been receiving abiraterone for the past three months. On examination, he exhibited signs of hypoxia and required supplemental oxygen. High-resolution computed tomography (HRCT) of the chest revealed bilateral ground-glass opacities, consistent with interstitial lung involvement. Extensive evaluation ruled out infectious, cardiac, and fluid overload causes. Given the temporal association and exclusion of other differential diagnoses, a diagnosis of abiraterone-induced ILD was made. Abiraterone was discontinued, and the patient was started on oral prednisolone at a dose of 0.5 mg/kg/day. Clinical and radiological improvement was observed within two weeks of initiating corticosteroid therapy. This case emphasizes the importance of recognizing rare pulmonary toxicities associated with abiraterone. Timely identification and management are essential to prevent morbidity and mortality.
Prostate cancer remains one of the most common malignancies among men worldwide, and the incidence increases with age.[1] In advanced stages, particularly metastatic castration-resistant prostate cancer (mCRPC), therapeutic strategies target androgen biosynthesis and signaling pathways. Abiraterone acetate, an oral selective inhibitor of cytochrome P450 17α-hydroxylase/C17,20-lyase (CYP17), effectively suppresses androgen production in the testes, adrenal glands, and tumour tissue. It has become a cornerstone in the management of mCRPC, often combined with low-dose prednisone to mitigate mineralocorticoid excess.[2]
While abiraterone is generally well tolerated, its adverse effect profile typically includes hypertension, hypokalemia, fluid retention, hepatic dysfunction, and, less commonly cardiac events. Pulmonary toxicity, particularly interstitial lung disease (ILD), is exceedingly rare and not widely described in post-marketing surveillance. ILD encompasses a heterogeneous group of diffuse parenchymal lung disorders characterized by varying degrees of inflammation and fibrosis. Drug-induced ILD remains a diagnosis of exclusion but is crucial to recognize early because it can be reversible with timely intervention.[3]
Abiraterone acetate is a widely used CYP17A1 inhibitor in the treatment of metastatic castration-resistant prostate cancer. It functions by blocking androgen production from adrenal glands, testes, and tumor tissues. While its adverse effects typically include hypertension, hypokalemia, and hepatic dysfunction, pulmonary toxicity—specifically interstitial lung disease (ILD)—is extremely rare but potentially fatal. ILD encompasses a group of lung disorders characterized by inflammation and fibrosis of the lung parenchyma. Drug-induced ILD remains a diagnosis of exclusion and requires a high index of suspicion. We report a rare case of abiraterone-induced ILD in a patient with multiple comorbidities.[4]
Abiraterone?induced interstitial lung disease (ILD) happens rarely but can be serious. The exact reason is not fully known. It may be due to an abnormal immune reaction or a sensitivity to the drug. Some patients are at higher risk, such as those with other illnesses like kidney disease, multiple myeloma, or those taking many medicines at the same time. In such patients, the lungs may react badly even after months of treatment without any problems.[5]
The symptoms are often general and can be confused with infections. Patients may feel short of breath, have a dry cough, mild fever, or feel very tired. In severe cases, they may have low oxygen levels and fast breathing.[6,7] To find the cause, doctors check for infections, heart problems, and other lung diseases. A high?resolution CT scan (HRCT) of the chest usually shows white cloudy patches called ground?glass opacities. When these findings appear in a patient taking abiraterone and other causes are ruled out, ILD should be suspected. Treatment involves stopping abiraterone immediately and starting steroid medicines like prednisolone to reduce lung inflammation. Oxygen and other supportive care are also given if needed. Most patients improve within days or weeks after this treatment, as happened in our case. This shows that early detection and quick action are very important in preventing serious complications.[8,9]
CASE REPORT
A 55-year-old male presented to the emergency department with complaints of acute urinary retention for one day, associated with chills and fever. He also reported new-onset shortness of breath and difficulty in breathing, which had progressed over the past 24 hours. His medical history was significant for systemic hypertension, benign prostatic hyperplasia (BPH), chronic kidney disease (CKD), and multiple myeloma for which he was undergoing chemotherapy. He had been on abiraterone acetate for metastatic prostate cancer for the past three months.
On physical examination, the patient was tachypneic, with a respiratory rate of 28 breaths per minute and oxygen saturation of 88% on room air. Bilateral fine crepitations were heard on auscultation. Cardiovascular and abdominal examination were unremarkable except for a distended bladder.
Routine blood investigations revealed elevated inflammatory markers but no significant leukocytosis. Arterial blood gas analysis confirmed hypoxemia. High-resolution computed tomography (HRCT) of the chest showed bilateral diffuse ground-glass opacities suggestive of interstitial lung involvement. Blood, urine, and sputum cultures were negative. Echocardiogram ruled out cardiogenic pulmonary edema. No evidence of pulmonary embolism or infection was found.
Given the temporal association with abiraterone and exclusion of other causes, a diagnosis of abiraterone-induced ILD was made. Abiraterone was discontinued immediately, and the patient was started on oral prednisolone 0.5 mg/kg/day. The patient was also managed with oxygen therapy and supportive treatment for urosepsis.
Within seven days of initiating corticosteroids, the patient showed marked clinical improvement. Dyspnea reduced significantly, and oxygen saturation returned to 95% on room air. Follow-up HRCT at two weeks showed substantial radiological improvement with reduced ground-glass opacities. The corticosteroid dose was gradually tapered, and the patient remained stable on follow-up.
Fig 1: HRCT Thorax
DISCUSSION
Abiraterone acetate is widely used in metastatic castration?resistant prostate cancer because of its proven survival benefits and generally safe profile. Most commonly reported adverse effects include hypertension, hypokalemia, fluid retention, and liver enzyme elevation. Pulmonary toxicity is extremely uncommon, and interstitial lung disease (ILD) associated with abiraterone has been rarely described in the literature. Drug?induced ILD is an important clinical entity because early recognition and treatment can prevent irreversible lung damage.[10]
In our patient, new?onset breathlessness, hypoxemia, and HRCT findings of bilateral ground?glass opacities developed after three months of abiraterone therapy. Infective, cardiac, and autoimmune causes were ruled out, and a temporal relationship with abiraterone was noted. On stopping abiraterone and starting oral prednisolone, there was marked improvement within two weeks. This clinical course strongly supports a diagnosis of abiraterone?induced ILD.[11]
When we compare with other reports, similar patterns are seen with other androgen receptor–axis–targeted agents like apalutamide and enzalutamide. Those patients also presented with diffuse ground?glass opacities on HRCT, and symptoms improved after discontinuation of the drug and initiation of corticosteroids. However, only a few case reports have specifically linked abiraterone to ILD, making our case valuable. It also shows that patients with multiple comorbidities such as chronic kidney disease or chemotherapy exposure may be at greater risk.[12]
Comparison with Other Case Reports
In our case, a 55?year?old male developed interstitial lung disease (ILD) after three months of abiraterone therapy. He presented with shortness of breath and HRCT showed bilateral ground?glass opacities. After stopping abiraterone and starting prednisolone, his symptoms and scan findings improved within two weeks. This quick improvement supported the diagnosis of abiraterone?induced ILD.
When we look at other published case reports, most involve different androgen receptor–targeted drugs such as apalutamide and enzalutamide. In these reports, patients also developed breathlessness and ground?glass opacities on HRCT after starting the drug. Stopping the medicine and starting steroids led to improvement, just like in our patient. This shows a possible class effect where similar medicines can cause similar lung problems.
However, compared to those reports, very few cases of abiraterone itself causing ILD have been documented. Most of the available reports are from Japan and Europe, and there are hardly any from India. This makes our case important because it adds evidence that abiraterone, though considered safe for lungs, can rarely lead to ILD, especially in patients with other illnesses like CKD or those receiving chemotherapy.
CONCLUSION
Abiraterone?induced interstitial lung disease is a rare but clinically significant adverse effect. Although abiraterone is generally well tolerated, new or unexplained respiratory symptoms in patients on this therapy should raise suspicion for drug?induced lung injury. Early use of high?resolution CT scanning, exclusion of other causes, and prompt withdrawal of the drug are essential steps in diagnosis and management.
Our case highlights that timely initiation of corticosteroid therapy can lead to rapid clinical and radiological improvement, even in patients with multiple comorbidities. Awareness of this rare complication among clinicians and pharmacists is important to ensure early recognition and to prevent potentially life?threatening outcomes. Further reporting of similar cases will contribute to better understanding of this uncommon toxicity.
REFERENCES
Vivek A K, Angitha Binu, Reshma Babu, Shaiju Dharan, Abiraterone-Induced Interstitial Lung Disease in a Patient with Prostate Cancer and Chronic Kidney Disease: A Case Report, Int. J. of Pharm. Sci., 2026, Vol 4, Issue 1, 3023-3027. https://doi.org/10.5281/zenodo.18378957
10.5281/zenodo.18378957
