The phrase "harsh side effects" is correct and usable in written English.
It can be used when discussing the negative consequences or reactions that may occur as a result of a medication or treatment.
Example: "Many patients experience harsh side effects when starting this new medication, including nausea and fatigue."
Alternatives: "severe side effects" or "adverse side effects."
Two experimental gonorrhea treatments are nearly 100 percent effective but harsh side effects mean they should be reserved for patients allergic to current first-line therapy, the Centers for Disease Control and Prevention said Monday.
Aggressive interventions including surgical removal of the bone and followup chemotherapy can have harsh side effects and are only partially effective, with 50% of these patients dying of this disease.
But this time, there were no harsh side effects.
By the 1970s, doctors had mostly stopped using it because of its harsh side effects.
Many poor countries now have only older drugs, some of which have harsh side effects.
Fungal infections are notoriously stubborn and hard to treat, requiring powerful drugs that can have harsh side effects.
It's a harsh side effect to measles – and, according to a 2010 study on the global burden of disease, diarrhea kills 1 million children under age five every year.
As GRE-regulated genes have been implicated in a number of glucocorticoid side effects, this is particularly exciting because it provides a clear avenue by which to reduce harsh side effect profiles currently limiting the use of these widely applicable drugs.
(Returning to the old vaccine, with its harsher side effects, seems neither politically possible nor appealing).
Of those seven, one had extremely drug resistant TB, which requires treatment with even harsher side effects and higher costs.
And their medications often have harsher side effects than those taken by people infected more recently as teenagers or adults because complications from their illness, or previous drugs they took and became resistant to, have made their disease more stubborn to treat.
