I have taken Rapamycin for 2 years at 5mg a week. In the last 6 months, I have developed fatigue, dry coughing and shortness of breath. My usual efforts to hike even a couple of miles have been challenging. I am a 70-year-old female with life-long, though well-controlled, asthma on the Trelegy Ellipta (1x/day) inhaler. After reading that a rare side effect of Rapamycin can be interstitial noninfectious pneumonitis with accompanying symptoms like mine, I decided to stop my weekly dose and see if I would feel better. It has been 7 weeks now off Rapa and gradually I am returning to my former energy levels with other symptoms resolving. If you have heard of this, can you weigh in? I don’t want to give up rapamycin altogether, but I also don’t want the accompanying lung problems. Thanks for your input.
Here is what Gemini Pro in thinking mode tells me:
Non-infectious pneumonitis (NIP), also referred to as mTOR inhibitor-associated pneumonitis, is a well-documented and clinically significant side effect of rapamycin (sirolimus) and its analogs (everolimus, temsirolimus). It is widely regarded as a class effect of mTOR inhibitors (Albiges et al., 2012; White et al., 2010).
Epidemiology and Incidence
The reported incidence of NIP varies significantly based on the patient population, the specific mTOR inhibitor used, and the diagnostic criteria applied (clinical symptoms vs. radiological findings).
- Sirolimus (Rapamycin): In solid organ transplant recipients, the incidence of clinical pneumonitis is estimated between 5% and 15% (White et al., 2010). Some regional studies in kidney transplant patients have reported a specific incidence of 9.7% (Üstün et al., 2015).
- Everolimus/Temsirolimus: In oncological settings (e.g., renal cell carcinoma), clinical NIP occurs in approximately 13.5% of patients, though radiological evidence of new pulmonary infiltrates—even in asymptomatic patients—can be as high as 38.9% (White et al., 2010).
- Severity: Most cases are mild (Grade 1 or 2), but Grade 3 events (requiring oxygen or interfering with activities of daily living) occur in approximately 3% to 4% of treated cancer patients (Gartrell et al., 2013; White et al., 2010).
Pathogenesis and Proposed Mechanisms
The exact molecular etiology remains a subject of active scholarly debate, with several competing or complementary hypotheses:
- Immune-Mediated Response: The most prominent theory suggests a T-cell-mediated autoimmune response or delayed-type hypersensitivity. Sirolimus may bind to plasma proteins to form an immunogenic complex that is processed by alveolar macrophages, leading to lymphocytic alveolitis (Alvarez et al., 2018; Ussavarungsi et al., 2012).
- Pro-apoptotic Signaling: Rapamycin may exacerbate lung injury by upregulating the pro-apoptotic transcription factor STAT1, leading to enhanced epithelial cell death and disruption of the alveolar-capillary barrier (Alvarez et al., 2018).
- Pro-inflammatory Paradox: While mTOR inhibitors are immunosuppressants, they can paradoxically promote the expression of proinflammatory cytokines such as IL-12, TNF-$\alpha$, and IL-6 in certain innate immune contexts, potentially amplifying an initial subclinical pulmonary insult (Üstün et al., 2015).
Clinical Presentation and Diagnosis
NIP typically presents within the first year of treatment, though onset can occur as early as a few days or as late as six years into therapy (Sağlam et al., 2025; Ussavarungsi et al., 2012).
- Symptoms: Non-specific, including non-productive cough, progressive dyspnea, and occasionally fever or fatigue (Atkinson et al., 2013).
- Imaging: Characterized by bilateral ground-glass opacities, patchy interstitial infiltrates, or organizing pneumonia (BOOP) patterns on CT (Albiges et al., 2012; Filippone et al., 2011).
- Differential Diagnosis: The primary challenge is distinguishing NIP from opportunistic infections (e.g., Pneumocystis jirovecii) or disease progression. Diagnosis is often reached by exclusion of infectious etiologies and observing resolution upon drug withdrawal (Ussavarungsi et al., 2012).
Management and Implications for Longevity
Management typically involves dose reduction or discontinuation of the drug. In severe cases (Grade 3+), systemic corticosteroids are employed, often leading to rapid clinical improvement within one to two weeks (Arunachalam et al., 2018; Sağlam et al., 2025).
In the context of longevity protocols, the risk of NIP at low, intermittent doses (e.g., 5-6 mg weekly) remains a knowledge gap. Most data are derived from daily, high-dose regimens in transplant or oncology settings. It is speculated that intermittent dosing may significantly lower the risk of such “starvation pseudo-diabetes” and inflammatory side effects, but long-term prospective data in healthy cohorts are currently lacking (Blagosklonny, 2019).
References
Albiges, L., Chamming’s, F., Duclos, B., Stern, M., Motzer, R. J., Ravaud, A., & Camus, P. (2012). Incidence and management of mTOR inhibitor-associated pneumonitis in patients with metastatic renal cell carcinoma. Annals of Oncology, 23(8), 1943–1953. https://doi.org/10.1093/annonc/mds115
Cited by: 130
Alvarez, R. H., Bechara, R. I., Naughton, M. J., Adachi, J. A., & Reuben, J. M. (2018). Emerging Perspectives on mTOR Inhibitor-Associated Pneumonitis in Breast Cancer. The Oncologist, 23(6), 660–669. https://doi.org/10.1634/theoncologist.2017-0343
Cited by: 23
Arunachalam, A., Ali, S. R., Wakefield, B. J., Lane, C. R., & Mehta, A. C. (2018). Everolimus induced pneumonitis in a lung transplant recipient. Oxford Medical Case Reports, 2018(4). https://doi.org/10.1093/omcr/omy008
Cited by: 5
Atkinson, B. J., Cauley, D. H., Ng, C., Millikan, R. E., Xiao, L., Corn, P., Jonasch, E., & Tannir, N. M. (2013). Mammalian target of rapamycin (mTOR) inhibitor‐associated non‐infectious pneumonitis in patients with renal cell cancer: predictors, management, and outcomes. BJU International, 113(3), 376–382. https://doi.org/10.1111/bju.12420
Cited by: 51
Blagosklonny, M. V. (2019). Rapamycin for longevity: opinion article. Aging, 11(19), 8048–8067. https://doi.org/10.18632/aging.102355
Cited by: 238
Filippone, E. J., Carson, J. M., Beckford, R. A., Jaffe, B. C., Newman, E., Awsare, B. K., Doria, C., & Farber, J. L. (2011). Sirolimus-induced Pneumonitis Complicated by Pentamidine-induced Phospholipidosis in a Renal Transplant Recipient: A Case Report. Transplantation Proceedings, 43(7), 2792–2797. https://doi.org/10.1016/j.transproceed.2011.06.060
Cited by: 28
Gartrell, B. A., Ying, J., Sivendran, S., Boucher, K. M., Choueiri, T. K., Sonpavde, G., Oh, W. K., Agarwal, N., & Galsky, M. D. (2013). Pulmonary complications with the use of mTOR inhibitors in targeted cancer therapy: a systematic review and meta-analysis. Targeted Oncology, 9(3), 195-204. https://doi.org/10.1007/s11523-013-0289-2
Cited by: 30
Sağlam, K., Köse, A., Yalçınsoy, M., Bayındır, Y., & Yılmaz, S. (2025). Everolimus induced pneumonitis in a liver transplant patient: Dilemma in the discrimination of pneumonia. Turkish Journal of Surgery, 41(1), 105-107. https://doi.org/10.47717/turkjsurg.2022.5489
Cited by: 1
Ussavarungsi, K., Elsanjak, A., Laski, M., Raj, R., & Nugent, K. (2012). Sirolimus induced granulomatous interstitial pneumonitis. Respiratory Medicine Case Reports, 7, 8-11. https://doi.org/10.1016/j.rmcr.2012.09.002
Cited by: 17
Üstün, S., Lassnig, C., Preitschopf, A., Mikula, M., Müller, M., Hengstschläger, M., & Weichhart, T. (2015). Effects of the mTOR inhibitor everolimus and the PI3K/mTOR inhibitor NVP-BEZ235 in murine acute lung injury models. Transplant Immunology, 33(1), 45-50. https://doi.org/10.1016/j.trim.2015.06.001
Cited by: 16
White, D. A., Camus, P., Endo, M., Escudier, B., Calvo, E., Akaza, H., Uemura, H., Kpamegan, E., Kay, A., Robson, M., Ravaud, A., & Motzer, R. J. (2010). Noninfectious Pneumonitis after Everolimus Therapy for Advanced Renal Cell Carcinoma. American Journal of Respiratory and Critical Care Medicine, 182(3), 396-403. https://doi.org/10.1164/rccm.200911-1720oc
Cited by: 265