Laravel- Handling multiple checkboxes in pivot tables

I have been struggling with this for a while, am a new developer with very little experience. So am working on a project dealing with drugs and diseases. There exists a many to many relationship.

Drug model

public $timestamps=false;

public function disease()
{
    return $this->belongsTo('App\Disease');
}

Disease model

public $timestamps=false;

public function drug()
{
    return $this->belongsTo('App\Drug');
}

I want to create relationships in the Disease_Drug pivot table using forms. form.blade.php

 <label>Disease</label>
   <select class="form-inline input-sm " name="disease" id="disease">
        @foreach($diseases as $key => $disease)
           <option value=""> </option>
        @endforeach
   </select>

 <label>Drugs</label><br>
        @foreach($drugs as $key=>$drug)
           <input type="hidden" name="drug[]" value="0" />
           <input class="checkbox-inline" type="checkbox" name="drug[]"value="" id=""> <br>
        @endforeach

  <button type="submit" class="btn btn-primary">Submit</button>

I have a disease_drug controller

public function form()
{
    $diseases = Disease::all();
    $drugs = Drug::all();

    return view('admin.form')
        ->with('diseases', $diseases)
        ->with('drugs', $drugs);

}
public function store(Request $request)
{
    $diseases = $request->get('diseases.ids');
    $drugs = $request->get('drugs.id', []); // Empty array by default if no checkbox checked.
    $diseases->drugs()->sync($request->input('drugs', []));
}

I am unable to save the results in the database. I am really clueless on this so kindly help me out.